The only reason I could think of is if you needed the taper to fit in the tuning machine, but that seems unlikely, given they work fine with giant rubber strings.
So, I’ll test it with those things here:
I’ll give feedback after putting them on (or failing to do so)
The experiment failed.
Strings are made for specific scales/mensures and thus my Kala Journeyman is untunable/got wrong intonation with the strings mentioned above. So that was a waste of money. I probably could’ve done more research beforehand and find this out with just theory instead of practice but then again - I guess it was worth my saved time and peace of mind. It’s not that easy to find U-bass strings. Somehow you’ll find either higher pitched ukulele strings or normal bass strings.
Next up are Pyramid U-Bass strings for a mensur of 53cm, which is what the Journeyman has. But I’ll probably keep this on my wishlist for christmas so I have something affordable on it.