I don’t have that much experience with higher tension steel strings, but I had similar ideas to Chris, so a good recommendation in my eyes.
The 3/4 Spiros are sold in Europe much more than the 4/4. So these are well developed strings. 4/4 are mostly used for 4/4 5-string instruments over here.
Thomastik tried to solve the breakage problem with the Dominants for a long time, but there was no solution and I can understand that. If something makes just a little cut in the monofilament core, the string breaks. And the windings cut first through the textile (silk) and later into the core where the strings bend and are moved just a little bit (bridge, nut, peg).
They highly recommend Spiros instead.
I asked about using downtuned Dominant Solos on a longer scale (110 cm) and they even didn’t recommend to use Dominants at this lower tension still because of the potential breakage problem.
I talked to one of the string designers/manufacturers about that some years ago at Musikmesse Frankfurt.
On my bass I rounded the bridge grooves and specially the peg side of the nut so that there is no hard bending at the peg side of the nut. I think this is very important for strings that are sensitive to breakage. But avoid clamping of the string in the nut grooves. If you round the pegbox side of the nut, you should also lower the nut at that side as much so that the string lies only with a third of its diameter in the groove.