Is your feature request related to a problem? Please describe.
The current options for registration (ANTs and niftyreg) are not great at cross-platform compatibility. eReg is a step in that direction, but needs further evaluation.

Describe the solution you'd like
It would be great to have ITK-Elastix as an alternative.

Describe alternatives you've considered
N.A.

Additional context
It has a huge advantage in that it is explicitly supported by the ITK consortium, so documentation (webassembly-specific), examples, and support are all plentiful.