Feature request : Watch list to Watched bulk conversion

Hi IMDb team! I have been using since almost 15 years my Watchlist to mark movies and episodes i actually watched. I have in there thousands of items i would like to convert to the recently introduced Mark as Watched list. I could go to click on each movies button, but i'd really like to keep the dates I added them to my watchlist as the date added referenced in the Watched list. I guess even more people used regular lists to keep track of their watched movies and shows before the Watched button was introduced, and i'm sure a lot of them would need the same thing feature as me. Would it be possible to introduce a tool to bulk convert Watchlist items to Mark as Watched, keeping the original add dates? This could be part of the "Edit list" menu? This same menu would benefit also of a few more tools, allowing to merge or split existing lists for exemple? Thanks for considering it! Best, Yan