EnCase export of PST/OST files

Fairly sure X-Ways processes OST files and, in a recent version (last 12 - 18 months), allowed handling of much large email files.

I am not proficient with X-Ways. Can we use it to process PST files?

Yes can be used to process both PST/OST and other email files.
Its basically an alternative tool to Encase (or rather Encase is an alternative to X-Ways D ) as opposed to a specific email extraction program.