My previous report of lock-up issues with both the standard Repeat
block, and a new OOT block that I wrote to allow variable interpolation
can be ignored.
The issue that generated my report was my use of a dual-input time sink.
I was feeding a base [0,1] signal into one input, and the interpolated
signal into the other. For some reason that caused the sink to lock up.
Using two separate time sinks, both old and new Repeat blocks run fine.
My new variable interpolation block works well!
Thanks to Marcus M. and Francisco A. for their assistance and
detailed explanation. I learned a lot through this process.