Mix shape keys, new shape key not in rig

[Edwin Cappelle]

Hello Thomas.
I have an issue with the Mix Shapekeys function.

When I don't overwrite the first, I enter a new name for the new morph shape key.
The morph shape key is added and present (in Object Data Properties), however it does not exist for the armature (it is not driven).
Then I import clothing and merge the rigs and transfer shape keys to the clothing.
Now the clothing will not follow the added morph shape key from the figure (even though it now has a shape key for the new morph).
Setting a value to the shape key on the figure should automatically set the value on the shape key for the clothing (like for custom morphs).

If however I do overwrite the first (which is a custom morph), the adapted shape key does as it should, but then the name is all wrong (still the original name which is not correct anymore after mixing shape keys).
There is no function to then change the name of the shape key.
I hope this can be fixed in some way (either rename shape key or make the new shape key behave like a custom morph).
Greetings.

[Edwin Cappelle]

Nevermind, I just found the Add Shapekey Drivers button under Advanced Setup, Morphs.
This does exactly what I need.
Greetings.

[Thomas Larsson]

OK, good. I rarely use the advanced tools myself, and don’t really remember what all of them do.