I'm using version .91 to trace bitmaps and convert to paths. The trace works great but has way too many nodes. The simplify path command is way too aggressive. I understand there is a way to adjust the simplification threshold, under File/Preferences/Misc - however the preferences menu seems to be under Edit/Preferences and no Misc category exists there. Can anyone tell me where to adjust the simplification threshold? Thank you!

Its right under 'Behavior'.

If you download the devel version of Inkscape 0.92, there is a new Simplification LPE.