Exactly. That is why GHS BN's are the front runner. Pure nickel has more mass than NPS, therefore more tension for the given diameter. The problem is string structure, which harpsichord makers have dealt with since the early 1600's: too thin, and you get bright tone at the expense of instability; too thick, and you get stability at the expense of good tone due to the string not being flexible enough to vibrate in its overtones. The TI E string has tension, but it is thumpy compared to the rest of the set. Even La Bella E strings are thumpy compared to the rest of the set. For most, that is the price to pay for playing a short scale bass: tone or tension. That is why GHS BN's are the leading short scale string. GHS through @Jon Moody have achieved a great balance between tone and tension that is just hard to beat.
Yes, the BNs are certainly one of the best short scale strings around, possibly THE best roundwounds.
I also like the Pyramid Pure Nickels 45-105. These are slightly stiffer than the BNs (hex core vs round coure I guess) but they still sound amazing. The added stiffness is actually a good thing on a short scale bass for MY playing style. The Pyramids are a bit clanky at first and they take forever to reach their broken-in tone, which can be a bit frustrating. I've also gotten several sets where one of the strings vibrated weirdly and caused fret buzz, typically the D-string. When I find a good set of the Pyramid PNs they NEVER leave the bass. Tonally I actually prefer the Pyramids over the BNs and the Pyramids last forever, like a good set of flats. The GHS BNs are definitely better balanced though.
My only real complaint about the GHS BNs is that they never last very long for me and they don't mellow out in a nice way, they go completely "dead" (at least for MY taste). I tend to prefer mellow, broken-in strings but with GHS BN I always need to replace them regularly. The same goes for GHS Boomers btw. Maybe it's a thing with GHS strings. I also like Boomers (on long scale basses, the short scale sets are either too light or too heavy for me) but their broken-in "sweetspot" seems to last for about 2 weeks before they go completely dead.
Brighter roundwounds has never worked for me on short scale basses. The increased amount of overtones just don't sound right to me with short scale.
I totally agree about the LaBella short scale set. LaBellas are amazing on long scale basses but too thumpy/muddy for my taste on short scale.
My favourite short scale strings in ANY category will always be the Pyramid Golds though. Actually, I think the standard Pyramid Gold short scale set may be the most balanced set of strings I've ever played. Maybe even better balanced than the GHS BNs. The long scale Golds are horribly unbalanced though, both tonally and tension wise.
On short scale basses I actually like D'Addario Chromes too and I absolutely detest them on long scale basses. The long scale sets are too clanky, stiff and unresponsive for my taste. On short scale basses that stiffness and added clarity is actually a good thing IMO.
The selection of great short scale strings is still rather poor though. With through body basses (like Mustangs) it gets even worse. I guess you can use long scale roundwounds in a pinch but I wouldn't do that with most long scale flats.