I’ve never had access to time stretching algos that sound good enough to use on a master.
But, I read that on David Gilmour’s “On an Island” solo album, when the final mixes were delivered they decided the album was a little too laid back so they sped tracks up marginally, trying several different algorithms to find the one that was most transparent.
I know it’s a very different kind of music but the principle’s the same…
Here’s the SOS article; https://www.soundonsound.com/people/recording-david-gilmours-island
Here’s the relevant part;
"One of the things Chris felt is that a lot of the tempos were too slow. It’s a fairly laid-back album anyway, completely overtly so, and David’s never been apologetic about that. He said ‘That’s where my head’s at, that’s what I want to do.’ But Chris still felt some of the tracks were too slow so we ended up, after a lot of experimentation, time-compressing some things using Serato Pitch 'n Time in Pro Tools, which is generally regarded as being the best-sounding time-manipulation plug-in out there. The time-compression was a very laborious process, but fortunately somebody else did it — listening to each part, deciding which algorithm worked best for which type of material! This was all done on a second Pro Tools rig in another room.
"There were a few things Serato didn’t do so well, but we got round it. For example, it really messed up the kick drum — it added some kind of backwards echo — so we just took some of the uncompressed ones and replaced them manually, lining them up in the waveform display. That didn’t take as long as you might think — maybe half an hour to an hour per song. It also enabled us to find a good loud one, a good quiet one, which suited Chris as he likes the kicks to be consistent and well behaved. It worked fine and it didn’t end up sounding like a drum kit made of bits.