I was looking at a size 48cm Flaanimal, 650b wheels with 48c Panaracer tires. Can you share the standover height?
The 49cm Flaanimal 5.0 shows 74.7cm standover with 650b x 2.1 tires. With a 48mm tire you would probably drop to about 74cm. If you were to drop to the 48cm frame (4.1 not 5.0) you would go down to 72cm. This is all an estimate because we do not have any 48cm frames built up but it should be close.