Wineserver and associated tasks not exiting when closing Lutris windows

Is this a bug or a feature?
Problem:
When exiting a Blizzard game and closing Lutris a lot of Win processes continue to run, among them agent.exe and battle.net.exe, but also several standard Win tasks. When you startup Lutris again, Blizzard starts a new instance of agent.exe and battle.net.exe, so if for some reason you have to restart several times (I’m debugging addons) you will run out of memory even if you have a considerable amount of it.
wineserver -k or wineserver -k9 managed to close wineserver and the standard Win tasks but all instances of agent.exe and battle.net.exe survived. This is bad considering the intrusive nature of agent.exe.
Only this command (which I don’t completely understand) helped:
ls -l /proc/*/exe 2>/dev/null | grep -E 'wine(64)?-preloader|wineserver' | perl -pe 's;^.*/proc/(\d+)/exe.*$;$1;g;' | xargs -n 1 kill
This easier one too:
wineserver -k; killall -9 wine wineserver; for i in `ps ax|egrep "*\.exe"|grep -v 'egrep'|awk '{print $1 }'`;do kill -9 $i;done

Would it be possible to include a button in Lutris to completely shutdown wine and close all associated programs?

Bug in Wine Staging.

After you start a Blizzard game (and close blizzar app): killall Battle.net.exe Agent.exe

Oh I didn’t know I could do that while the game’s still running. Thanks.

Is the bug reported?