Thanks for answer, Yutaka.
” incorporate to Undo” sounds fine. Good idea.
I am only afraid that we can lose an selection on other occasions too (not only after doing an real action).
E.g. by mistakenly clicking elsewhere after a long, carefully done selection over many “pages”.
That’s why I developed the above suggestion.
But restoring selection on Undo would just work fine for the majority of cases, I guess..