Hey Dennis,
You answered your own question within your question: a given capo's curvature cannot possibly accommodate different radii fretboards. Some have softer rubber compounds to allow for more variability in curvatures, offering the user the potential for using it on boards with different radii, but it's not a perfect solution as you inevitably have to tighten the capo more to squish the rubber in that area where the radius of the board and the radius of the capo don't match. And we all know that the more one squishes, the greater the likelihood of pulling those strings sharp. Yes, not a "fix" by any means! The solution is find the one that works best for that guitar's radius.
FWIW, I've found both the G7 Performance and the Planet Waves Dual Action Trigger to have excellent curvatures for my Taylors. That said, I only use the G7th 12-string version for my 12-er as it seems to be the only one that works well with the least amount of "squish" required for the strings to ring true.
Edward