I'm glad you posted this. As you can read from my posts up a bit on this page, I am also having issues with running 2 binhex-qbittorrent containers. I thought initially it was due to the fact that I had routed the traffic of the 2nd one through the 1st. But when I separated them completely, eaching routing the traffic through Bridge and giving them each their own wg0.conf, the problem remained. So the cause had to be something else.
When I read your post, it has nothing to do with the traffic routing, but with having both webUI's open in the same browser.
So are you saying that if you open the first one as http://192.168.1.1:8080 and then second one as http://tower.local:8081, then there is no memory issue? As long as the hostname is different?
Have you also just tried running one webUI in chrome and the other in firefox for instance?
Edit: Can confirm both methods seem to do the trick!
@binhexis this something you would look into?