Yes, this looks like an issue, indeed. That check only makes sense for pooled and pooled-lo, so it should not be applied for hilo.

Unlike pooled and pooled-lo, the hilo generator uses the increment_size to multiple the hi value while the hi value is incremented with a step of 1 on the database side.

So, this should be an easy fix as it just needs to skip the check if the strategy is hilo.