Hi -- first post, though lurk regularly to see what folks are doing. Wanted to give
@RMerlin a picture of my RT-AC86U.
Beta history: upgraded from 384.19, always dirty, every beta. I have a great deal of dev (kernel / rom) flash experience in embedded devices; rarely do I find anything in nvram data that would require a reset -- I have scripts to notify me of changes from version to version upgrades so I can surgically fix if needed. None needed for any of the betas.
Beta results: Generally flawless. One smart tv, a local 4G cell expander and one google mini home needed reboots in Beta 2, no biggee, just noticed device failures logging in. Those devices were on a guest network (1). I do see some folks getting upgrade messages in Beta 4 on this router, I received no such warning -- just worked. I can't speak to the issue otherwise.
Environment: I run multiple VLANs for various isolation reasons and have extensive startup scripts to setup the VLANs (robocfg, dnsmasq adds, host adds, etc.) firewall/nat, ebtables, tinc mesh vpn (managed via entware startup) between my router and multiple other sites (family gaming), etc. Point is, my router is heavily configured at many levels, which speaks to the stability of the betas.
Temps (syslog output from regular cron job): Very consistently (literally every 10 minute check) around CPU: 79 | 5G: 70 | 2.4G: 63 (wireless the same for guest network wl.x values). /proc/dmu/temperature used for CPU temp, wl -I [ethX | wlX.Y] phy_tempsense used for radio temps.
I guess the point is, all is pretty much normal and I've seen zero issues so far other than the odd need to reboot a few clients in Beta 2 (not worried about that at all).
Hope it helps.