Weber, Matthias schrieb am 30.05.2020 um 21:18:
Dear List,

After staying with a frozen MKIV version for time-critical work for a while, I took the plunge and ran one of my longer math-heavy documents through LMTX. To my delight, it mostly looks fine or trivially fixable.
There is one problem I have with enumerations. The spacing between them in LMTX is notoriously smaller than in MKIV. 

No, it's a problem with framedtext which uses the wrong placement option and ignores the before/after values.

I bet there is a parameter I can set to tweak that? Below is a MWE with output for both engines. 

There is nothing you can do here except waiting for a fix but I noticed the location key for framedtext has a not existing value (no paragraph option exists) in your example.