Looks interesting. I am using a similar setup with Debian 11 + KDE and i3 and urxvt in Damon mode. You get all the benefits of Settings, Network Manager, Keychain etc. and just use i3 as your Window Manager I used to have Gnome. But since switched to KDE5 as I read that KDE 5 takes less memory than Gnome 3
Heads up here regarding KD. Since you're using Debian I guess you don't have the latest. At one point I think Debian will switch to KDE Systemd, and it will break your login script that launches i3. A solution is to use Systemd units[0] at one point I might write a blog post about that.