What should be done with edits made by unregistered users to their own posts?

Question

I just came across this edit suggestion review. This is not the first time I have seen this unregistered user or some other similar user making drastic or overwhelming edits to apparently their own posts which almost always change the post completely e.g.:

1. Edit 1
2. Edit 2

Naturally I always reject them because I have no way of knowing if its the same person or someone else with the same name.

Yet given the persistence and writing style, I am almost sure its the same person but lacking any substantial evidence, I feel my hands are tied in this matter.

What should be done with huge edits proposed by an unregistered user to apparently his own previous posts?

Answer 1

I asked a similar question on meta.scifi. The answers recommend rejecting a substantial edit with a custom reason linking the user to the instructions on how to recover a lost account. There is a similar question and answer on Meta.SE.