Edit: it's GTK that provides multithreading functionality, not VTE itself.
VTE based terminals are actually multithreaded globally, so you only ever have one process regardless of number of tabs/windows open.
But I agree, VTE is something I avoid ever since the scrollback fiasco. (For the uninitiated: the library wrote all scrollback to disk, which is not something end-users might expect security wise. Scrollback is encrypted now, but it appears you still cannot disable writing to disk, as e.g. the output of dmesg, consisting of 62210 bytes of output on my machine, causes 5-digits of bytes to be written each time on any VTE-based terminal I've tried even with "infinite" scrollback disabled. And none appear to honor TMPDIR).
The O_TMPFILE flag is just an anonymous file as far as I understand. From that source file, VTE uses glib, particularly g_get_tmp_dir() and g_file_open_tmp() (which uses the latter), which claims to honor TMPDIR according to the docs: https://developer.gnome.org/glib/stable/glib-Miscellaneous-U...
Perhaps a terminal emulator is unable to read variables exported in .bashrc, as the terminal is started prior to executing the shell.
I prefer tmux windows; I have 1-3 terminal emulators and 10-30ish windows/tabs (not counting splits/panes), all on 1 tmux session via `tmux new-session -t $SESSION`. Acceptably navigatable via prefix-[1-9] and prefix-w (which gives a list to jump to).
I find tmux makes less sense within a tiling window manager because then you have two contexts effectively providing the same functions (or three, if you use vim :split (or four, if you use tilix)).
I also use a tiling wm, and use tmux. The main reason is that it means I can easily transition to using the same tool when working with remote machines using mosh. Personally, I've always felt odd when trying to use i3 tiling for terminals (maybe that's because I used tmux before I used i3).
Also, to the other commmentator- be glad its not written in "modern web technology". I keep 20 terminals open usually.