This shouldn’t be too difficult to implement (though I’d strongly favor a version where the universally allowed qualifiers are just a static list in the extension configuration – a class statement on the property entities would be a lot worse for performance), but it might not happen soon. In the meantime, it might help to add those qualifiers to “allowed qualifiers” constraints explicitly, e. g. by plugging the results of this query into QuickStatements.

Final discussion : https://www.wikidata.org/wiki/Wikidata:Project_chat/Archive/2020/01#Deprecation_and_preferred_rank

I understand the need but we are making the system more and more complicated. Would it be ok for the time being to follow Lucas' advice and do a quick quickstatements run?

Yes of course.

Running the first batch now.

As @Esc3300 @Jura1 has already reverted a couple of these, I am holding off running more batches for now. Posted on their talk page.

Tagging @MisterSynergy

Update: I plan to start running batches again today or tomorrow, manually removing any properties that have been reverted on prior runs. So far there are only 4 of them, so this approach should be manageable.

Thank you! ❤

Completed for all properties through P6801 except for a few that have been reverted. Big thank you to whatever team got QuickStatements working again.

I added a note to the constraint type documentation, feel free to improve it: https://www.wikidata.org/wiki/Help:Property_constraints_portal/Qualifiers#Universally_allowed_qualifiers