Comment by krferriter

I don’t agree. On an encrypted volume all space unallocated by the filesystem should have random data in it and should be indistinguishable from the portion representing in-use filesystem data. Deleting data securely involves overwriting all the previously allocated filesystem blocks with random data. No one should be able to discern that now-empty space had data in it as of some specific recent datetime.

There may be more OS design decisions you have to make to cleanly wipe all references to particular app or process names but to me it all seems doable.