LOL, that was quick, gonna need to come up with something more challenging for you. ;)

If I may nitpick: in the last screenshot there, you can see the line segments in the curved root line. Is it possible to use smaller steps so it looks smoother?

The height of the fin tab does not auto calculate correctly.

1. Create transition with inner tube and centering rings.
2. Add freeform fin (default).
3. On Fin tabs tab, left-click Calculate autimatically.

Results is fin tab height that goes to centerline of transition.

If I may nitpick: in the last screenshot there, you can see the line segments in the curved root line. Is it possible to use smaller steps so it looks smoother?

Done, export now looks like this:

The height of the fin tab does not auto calculate correctly.

1. Create transition with inner tube and centering rings.
2. Add freeform fin (default).
3. On Fin tabs tab, left-click Calculate autimatically.

Results is fin tab height that goes to centerline of transition.

That's not a result of this PR, so there should be a new issue created for it. Also a side note: if the transition's fore diameter is smaller than the aft diameter, the calculations is done correctly. It's only when the aft diameter is smaller than the fore diameter that the tab height is calculated incorrectly.

Actually, the cause was user error on my part. . . I failed to check the inner tube "motor tube" checkbox. With that box checked, the automatic fin tab height functions correctly.

Functions as expected, no anomalies found.

Build 918
[Windows 11 Pro; Version 21H2; OS Build 22000.739; Windows Feature Experience Pack 1000.22000.739.0]
[Java "11.0.15" 2022-04-19 LTS; Java(TM) SE Runtime Environment 18.9 (build 11.0.15+8-LTS-149)]