…Did the chances of a "Rare Success" go up accordingly?
I’m guessing no, but I haven’t been keeping track.
The “success” results are more profitable than they used to be. E.g. upconverting T4 wines used to give 4 Mysteries of the Elder Continent, now it gives 8. I don’t know if the rare successes are either more profitable or more common.
I honestly think the favors ought to be a Renown requirement. No need to make conversions so expensive, especially when people rely on them for their Notability.
Favours are not required for the third-tier conversion carousel, and the second-to-third up-conversions have bulk options that do not require favours (in addition to being more action-efficient). If Summerset and Benthic are converted to the favour/renown system at some point, then favours will affect the Extraordinary Implications off-ramp, but the chief result of that would be to make the full carousel more appealing.