I was wondering if a Filter might be the solution. The RescaleFilter you propose looks like it would fit our needs well. I’ve followed up on email as you suggest as well.
Lossy compression filters in general are interesting here. The precision reduction seems to really help downstream compression filters to work well. I did try the bit width filter but in my test it didn’t have the drastic improvement in file size that manually reducing the data type to int16 did, but I’ll get some harder numbers.