pleasant surprise to see this tool get reworked.
two minor things i've noticed:
1) if you resize the whole window to be short enough, the Text Preview's window will have the Custom Text row dropdown overflow ontop of the Text Preview tab. I imagine it shouldn't move overtop the tab and instead stay in place.
2) While I see the value of clicking text in Text Preview, having the current character I'm working on have a different text effect in Text Preview is distracting when trying to ensure that particular character I'm editing is cohesive with the rest of the text. Maybe a toggle to disable this, or the highlight occurs whenever you hover over anywhere on the outputted Text Preview area?
3) +1 on stormgold's request above: "Allow auto-set advance to go down to 0, or even lower. (The old version allowed this to be set to 0, which is often very handy. Now it won't go lower than 1.)
One larger thing I was curious about is the feasibility to create specific kerning rules for specific character sequences eg. if A precedes W, reduce spacing by 1px.
anywho, much appreciated the work put into this. i've used this specifically to create some custom fonts for open source hardware.