Totally, but it’s their choice and their artist career at the end.
Top artists also choose that way… for good reasons (I suppose, dunno which one…)
If you propose a hotter master, I bet the client would choose it, whatever explanations you’d give…
I think you may try to do something between what you expect and client’s expectations… (at least 
)
Edit: by the way, it’d be time to close that project and move on to the next one 
I find Reaper does an excellent job whether speeding up, or slowing the tempo while still keeping the same pitch. I used to try this on the standalone machines I own/ owned, and I tended to get a lot of audio artifacts. I’m really impressed with Reaper.
Ah! Gotchya. So u didn’t have any control over the mix. I’m pretty ignorant of most mastering related topics so I don’t think I could comment on anything meaningful in that regard. Interesting discussion though