Allow importing of Wetrakr export

I want to mass relabel some historical data/times watched of old shows which have incorrect timestamps, and the ui method of changing dates/timings of watch history is very slow and manual (no multi-select, no sensible timing organisation so episodes watched are shown in order). I exported via https://wetrakr.com/profile/settings/data but was surprised to see there was no method to import a Wetrakr export.

If importing on an existing account, it should skip over existing content, and only import new/changed content. A pop-up clarifying whether existing information that isn’t in the new import should be removed/kept, and a 2nd one clarifying whether the new information should be added or not would be ideal, for complete control (and to be able to avoid changing the date of a watch and then keeping both the original watch and the new updated watch).