Is it permitted to sign with a stamp on Chol Hamoed?

Some opinions[1] rule that this is forbidden [Maaseh Uman]. Others hold[2] that it is permitted [Masseh Hedyot]. Seemingly when done for a Chol Hamoed need one may be lenient, as according to all when Maaseh Uman is done for a Chol Hamoed need it is only a Rabbinical prohibition, and thus one may be lenient in a case of doubt in a Rabbinical prohibition.

^[1] Elya Raba 460:6 in name of Amrakel regarding cake molds

^[2] Ashel Avraham Butchach Tinyana 545; This is despite the fact that he rules that doing Melacha on Chol Hamoed is Biblically forbidden