I'm probably going to return these so I debated whether to bother even writing this. I generally don't bother as having worked in tech for so many years I understand how little concern there usually is for customer concerns especially those I'll admit may be outside the norm. In any case here goes...

1. I replaced some quite old Orbi RBR50 mesh routers with a new BE63 triple mesh setup. Getting it running wasn't that easy as the BE63 doesn't seem to like initializing when the WAN is not up. Since I was having problems getting the BE64 to properly connect to my cable MODEM that meant that other than getting the pretty red light saying it wasn't happy the BE63 wasn't very useful in helping me see what the problem was. The WAN simply wasn't working and therefore the BE63 wasn't going to work either. Eventually I sorted out the cable MODEM issues and at least it was alive.
2. Basic configuration of the BE63 and connecting devices to it is pretty simple. If one just wanted to plug stuff in and have the Internet alive  I would say it did ok here (after resolution of #1 of course).
3. Performance is quite good and I'm happy with that. The WAN connection is slightly faster (due to 2.5 Gb/s ports instead of 1 Gb/s on the Old Orbi).
4. The app is nice but I'd prefer configuration via a web page. Maybe I'm old school but navigating through a series of small screen menus just doesn't seem better than a nice large, comfortable web page to me. I know everything has to have an app now and the Orbi had an app also but for anything significant I used the web page on the Orbi instead of having to squint at the small menus on my phone and go back and forth through dozens of menus.
5. The good news is basically over at this point. First, I was running PiHole. I was using it as my local DNS server. I had this notion that I could turn off the DHCP server in the BE63 (or the auto disable would take care of that for me). I have failed to get that to work. If I have the PiHole connected to the BE63 when I power it on all I get is a red light and nothing works. I have no indication of what is going on from the BE63 at all. It is simply unhappy about something. If I connect the PiHole later it appears the Smart DHCP on the BE63 eventually sees there is another DHCP server and disables it's own DHCP server. Of course at this point the damage is done and the BE63 already handed out many leases which the PiHole is not aware of. I saw a recommendation about setting up PiHole to use the same DHCP address range as the BE63 and I'll admit I haven't tried that yet. I have a few weeks before I must file a return with Amazon so perhaps I will try that before giving up in total frustration.
6. As a backup I thought to set up a dnsmasq DNS server on my local network. Configure the BE63 to report that as the DNS server via the DHCP settings. That works up to a point but is so severely unreliable that it basically can't be used. The issue appears to be that the BE63 advertises the IPv6 DNS serves from the WAN side to the LAN side. However, The BE63 DHCP settings only seem to allow setting the IPv4 DNS server addresses. No obvious means to override the IPv6 DNS servers for the LAN clients. So my clients randomly pick their favorite DNS server which may be my local dnsmasq server or one a public server from the IPv6 list. Sigh....

So why do I need a dnsmasq (or some other local DNS server). Because the BE63 is a DHCP server but not a DNS caching server. That means while you can configure fixed IP addresses and given them nice pretty names Those names are not usable to refer to the clients. So none of my local servers and services can have pretty names unless I create hosts files everywhere. I've done that before and while I could go back to that brute force approach I prefer not to.

I know running my own NAS and other services locally is likely not the target audience TP-Link is aiming for.  That's fine and they're obviously allowed to build their product as they like.

I guess being able to refer to local devices by names rather than IP addresses doesn't fit into the overall user friendliness mantra the BE63 (and entire Deco line it appears) is designed for. That doesn't really make sense to me. I've seen lots of threads about people asking them to allow disabling the DHCP server. They've finally done so for access point mode but not router mode. The claim I saw was that all their "value add" features rely on them being a DHCP server. Those value add features and subscription based and I am loath to accumulate any more subscription based services. That is especially unpalatable when subscribing to said services would not solve my DNS problems at all. Simply provide services I got with PiHole for free and honestly could do without anyways.

So I can't really buy into the excuses for allowing complete disablement of the DHCP server. Sacrificing flexibility for user friendliness doesn't seem necessary or even beneficial in this situation. Having been a firmware engineer (and manager) for many years with lots of network experience, although that's not my primary expertise, this situation really makes zero sense.

Not being able to disable the DHCP server when lots of other companies allow that is odd. Having the capability of naming everything but not having DNS to enable use of those names throughout the LAN is inexplicable. Being able to set IPv6 DNS server addresses on the WAN side but not the LAN side is a major oversight in my opinion. Either support the appropriate features, i.e., local DNS, IPv6 DNS addresses for DHCP/LAN, etc or allow DHCP to be turned off so users can roll their own solution.

I know that comes across as a bit "ranty". I don't really mean it to be.There is some frustration over trying to press a round peg into a square hole (or something akin to that.