"Yet".

I actually wanted to do something quickly first, so I was too lazy... I figured worst comes to worst, it will crash and prove I need to recompile it.
Qt Designer crashing -- I saw a thread on the Arch forums:
https://bbs.archlinux.org/viewtopic.php?id=210622
Qt5.6 deprecated Qt WebKit *and* Qt Quick 1 -- well, apparently Arch doesn't package qt5-quick1 anymore so when you `pacman -Syu` you end up with an outdated abandoned and incompatible qt5-quick1.
If you need it it is in the AUR now...