Running Konversation with QT_SCALE_FACTOR=2 on my lodpi screen...
LowDpi works as well:
I am tempted to propose this for 1.7.6 still, but I can see why one would rather not risk adding such a change 2 days before planned release :)
Doing some 1.7.7 in a month with perhaps other fixes should be fine.
See bugs 392811 & 341364