I have an idea for a new feature, the openwrt image could have serial built-in verification and enable - loop prevention/detection. The LAG (Link Aggregation Group) function would be useful, especially with a WiFi 5 dual band connection. Probably there would be some software solution that simulates a dual wifi dual band connection or software wifi 6.
Openwrt supports LAG, but there are devices with 2.5gbit ports...
I wanted to suggest as part of the solution regarding the wifi 5 dual band loop
wifi 2,4GHz and 5 GHz —> (wifi 5)
For wifi5, coupling 2.4 GHz and 5 GHz wireless into a (virtually) single link causes you nothing but pain, without any gains. The throughput expectations between them are just too disjunct to make this useful, while inheriting all the problems of managing the situation.
For wifi7 you'll get it via MLO (which is currently under active development), but that will usually imply MLO 5+6 (much closer in terms of expected throughput), rather than MLO 2.4+5 (yes, this could improve your link stability, but most client devices won't do it (just the way real-world hardware/ firmware/ drivers is set up so far)).