PVC-E is just as easy as hide glue to remove from wood.  First off,
I'm not advocating that PVC-E should replace hide glue or fish glue,
etc., as these are very much time-honored and historically accurate.
Hide glue is more reversible but only because more people know how
to go about removing it.

Occasionally (not usually) hide glue gets _really_ brittle it scrapes
off and almost crumbles off easily (in that instance the hide glue is
easier to remove).

I also like hide glue better because old hide glue doesn't have to be
entirely removed from the wood.  New hide glue will adhere over the old
remaining hide glue better than hide glue would adhere to a "less than
thorough job" of removing PVC-E from the wood.

I have posted before here, twice, that finish amalgamators will soften
the old PVC-E enough to where it can be "pretty easily" scraped off
with a razor blade.  I found another product which works even better:
liquid stripper (paint remover).  Try it, it works great!

I am using PVC-E as an adhesive for replacement plastic key tops.
Occasionally one chips when I am trimming it on the router table and
it has to be done all over again.  First I steam off the chipped key
top using a hot iron and a damp terry cloth (it comes off easily).
Next, I brush on the liquid stripper, wait one minute and then easily
remove the chipped top with a razor blade, then sand and reglue another
key top.

Bill Maguire