Quickly scanning through the fork on github I figure it should be possible to change the size to 2048 samples per slot.
Remember - The original WaveEdit only works with 256 Samples / Slot which is just 1/8 of the 2048 samples per Slot Serum is using.
Find the 1024 Samples/Slot fork here: https://github.com/jeremybernstein/WaveEdit/releases/tag/v1.0-alpha.3