(This is a long-standing compiler issue; not a regression from the new compiler.)
These projects display differently when compiled
https://scratch.mit.edu/projects/1219497763/
https://scratch.mit.edu/projects/1219599142/
Not clear if anything can be done to fix that aside from telling people to use the join block if they need a string. Maybe don't do conversion if there's more than 6 decimals, but that seems likely to slow down any projects storing mathematical constants in variables. Or maybe we can just make the variable monitors not round, but then that will cause breakage in the other direction when they display 0.30000000000000004 instead of 0.3