I went IPv6-only for everything internal. The only thing that’s dual stack is the wireguard server running on the gateway. I haven’t run into any issues, mostly because my Linux distro’s package repository has many IPv6-compatible mirrors (enabled by default). For anything not in the distro’s repos, I build from source and package them up into RPMs myself, so as a side-effect, I don’t have to deal with eg. Github not supporting IPv6.
Even things with generally crappy firmware, like the APC UPS management card, Supermicro & ASRock IPMI management interfaces, etc. have worked fine in an IPv6-only setup for me.
I primarily use Alacritty. I spend quite a lot of time running things that produce ludicrous amounts of output (eg. compiling Android from source). Out of 10 or so terminal emulators I’ve tested earlier this year, it was the only one that didn’t use 100% CPU displaying all that output, staying in the low single digits.
I’d prefer to use Wezterm because I like its lua configuration system and the builtin pane splitting, but with my workload, I still run into issues where its CPU usage shoots to 100% and becomes non-responsive for a while. (That said, it’s already a lot better than before. I try to report any issues I can reliably reproduce and Wez has been wonderful about fixing them.)