Well....many devices are running their own WRT variant, but variant is variant, it's not the same thing, even the FriendlyWRT and the one comes with GL-INET are based on OpenWrt, however when problem comes up you may not be able to get the same support/fix on the official one.
Only using it as AP, what are you expecting? The famous Unifi AP is still using MT7622 which is even older and lots of people using it without problem
Indeed. Suggesting is one thing, but comments like "you shoot yourself in your foot" and "sorry mate it should not be based on what looks cool" are not helpful at all 
Guys, im not insisting on anything, just providing input... as for firmware, im not speaking on firmwares like Rooter Os, of FreindlyWRT... but i am aware firmware exists for the device based on 23.05. either way... its not my project nor my decision, its just insight. and I wouldnt be deploying anything less then AX right now in regards to the performance and ubiquiti comment. They will do what they decide to do. All i know is its a solid choice and will get the job done, as well as the WAX probably would also .
Are you looking into a setup where the main router is tucked somewhere away, while wired to an access-point which is located centrally in the shop?
If so then a core router like NanoPi R4S 4Gb would be a possible fit - this will also have some headroom in case you decide to install additional services like SQM.
Do you have a preference for wall- / ceiling mounted access points ?
If so the Netgear WAX220 and ZyXEL NWA50AX Pro are good candidates indeed.
I can confirm, it was not the plastic case that I was commenting about lol...or even the form factor. The specs looked pretty good for what it is as a router, honestly was surprised about having 2.5GbE for that price, not that this use case needs or would even make use of that.
Yeah, I don't think I need x86. The captive portal they want is very basic. Basically a web page with terms of use for the network that people have to agree to. They're not looking for anything crazy.
Yes, this would be the idea. The main router does not HAVE to have WiFi, not necessarily a bad thing if it does and it might even get used if it does but it's definitely not a requirement given it won't be located ideally for it.
It would have to be wall mounted. I asked for pictures of all their Ethernet drops and none are on the ceiling although that would have probably been ideal. Not that I think the mounting location makes a super big difference in terms of model options? Might be wrong.
If the price of R4S are good in your country, then go for it (I own both), in my home I have > 40 devices and R4S is really really great, with USB powering + little metal case it can be hided somewhere (or stick together with AP)
For a real world example, see here:
I have seen this implemented successfully many times in the same type of environment so this is not just a one off.
This even implements optional "fair usage policy" where a user is encouraged to move on if they outstay their welcome - quite important in a coffee shop if a customer is taking up a seat and has stopped making purchases for example.
All on a bottom of the range budget mini-router.
For the core router, EdgeRouter X is also an option - this has 4 lan ports so multiple access-points can be connected without the need for an extra switch. The caveat with this device is that SQM is not really possible.
One more thing to take into consideration: do you prefer to power the access-points via PoE (i.e. for more flexibility in placement, or for a cleaner look) ?
=> in that case could you can opt for a combo like NanoPi R4S router + Netgear GS305EP switch + access points (the PoE-only powered Ubiquiti UniFi 6 Plus is an additional access-point option in that case)
Yes, if you are sure you do not want wifi, it is pretty good. Only problem is, I am pretty certain it is no longer manufactured. A few "new-old-stock" pop up on Ebay every now and again, as do second hand units....
This is supported by current OpenWrt 23.05.03 stable version, but builds have been disabled in the main development branch due to insufficient room for the kernel version that will be used in the next OpenWrt stable release. Until the developers make a decision to modify its flash layout for future support, I would be hesitant to choose an ER-X.
It's a great device within its limitations (ISP service slower than 200 Mbps, or used with its hardware offload and no demanding CPU loads - including no PPPoE), but the ER-X MT7621 CPU is a bit on the slow side these days for a gateway router. CAKE SQM tops out around 100 Mbps, Wireguard VPN ~150 Mbps and forget about OpenVPN.
Paired with a NanoPi R4S as a gateway router, and for the right price, I think the ER-X would still make a fine managed switch (kept on OpenWrt 23.05 if that is the last supporting OpenWrt version). Since the ER-X is a router, it's easy to miss it can be quite cost competitive with 5 port managed switches, for which it is obviously quite capable.
I wouldn’t hesitate using something like a R7800 with non-ct driver/firmware, which can sometimes be found for pennies used.It has one of the best range, if not the best, of any Openwrt routers. I’d even recommend using snapshot which will make it easier to upgrade in the future. (After current 23.05 stable series, it has been ported to DSA).
The R7800 has had a good run, but I think it's past out of date.
While main snapshot does support DSA on the R7800, DSA also comes with a non-trivial performance hit on ipq806x targets. I'd keep an ipq806x target like the R7800 on 23.05 for as long as it was supported for this reason. Even then, ARM A53 CPU cores in more current offerings make the once fast R7800 CPU look a bit tired.
As an AP, the R7800 does not support 802.11ax, which could be an issue in a business area with interference from many competing AP's and a large number of clients.
Were it not for the OP's clarification that an all-in-one is not a good fit (the AP's are being wall mounted and a router needs to be located separately), even at $160, I would recommend a GL.iNet GL-MT6000 (Flint 2) to keep customers in my business happy over an R7800 for pennies. Easy for me to say though - it's not my money .
Figured I'd give everybody an update here. I was going to go with the GL-MT3000 and a Netgear WAX220 but the MT3000 was going to take too long from amazon so I ended up getting an R4S as the main router instead. Thanks for all the suggestions guys, it was really helpful.
Let us know if you can how did all go with that one. Maybe the R6S could have been better. it has 2.5G
Even R4S is an overkill for OP, and not to mention that R6S still doesn't have support yet.
Will do, I'm still waiting for parts to arrive. I have everything except the R4S, that should be arriving tomorrow. Also I really don't need 2.5G, the switch I got is only 1G, their internet won't even be that and they basically have no local network traffic so 1G is plenty.