Okay this feature is in for the next update! I should have done this faster, but I was afraid of how using best fit on multi-line text would work, but it works great!
There's now 3 options for best fit...
"Off" (which is just how STm behaved before, no changes)
"Always" which will always make text be as wide as the autowrap limit.
and "Over Limit" which will make text fit within the autowrap limit, but only shrink it to fit, not enlarge it to fit.