I can confirm that ~customProperties are now calling cellActions.willConfigure in STV 5.3.0.
Hurrah! Thanks Tarek!
cellActions.willConfigure wasn't always called by ~customProperties in some earlier versions of STV, see here:
But, ~customProperties seem to be calling willConfigure 4 times, and then willDisplay twice.
I thought that willConfigure was only called the once for a cell. 4 times seems a bit excessive. It doesn't matter, it is all working now, but is that how it's supposed to work?