"It's simply impossible to go beyond fart factor 10." \
"Eject the fart core!! (rip)" \
"I'll execute you just like Tuvix if you ever change the type of beans in my coffee specification again!!" \
"We monitor for species that are on the verge of achieving the fart-drive technology." \
"Bean me up, Scotty." \
"The fart field extends around the ship traveling through fart-warped space, it's like hot-boxing or Dutch ovenning." \
"Foton torpedo, target their starboard fart-box, on my mark!" \
"Warning! Incoming fart signatures!!" \
"Do not reverse the polarity on the engine drive or we will all instantly get pink eye!!" \
"Who put hot-sauce on the Difarthium crystals?? The ship can't take the extra boost!!" \
"Wesley, go clean the warp anuses!"
... all these scales can go to infinity regardless of if they are logarithmic or not (if I understood your complaint correctly).
And you are right, warp 10 isn't the maximum, just an (energy consumption of that) tech limitation. And also that is very ship-capability specific - eg crew's experience on a warp 7 ship going from 7.0 to 7.5 is not at all comparable in any practical navigational reasons to crew's experience on a warp 9 ship going from 9.0 to 9.5.
I don't think the warp 10 being infinite by default is cannon tho:
If every butt had a tiny airlock 2 door system that operated to a very accurate degree of opening and shutting just when the farts came out, and all simultaneously, I believe frozen butts can be avoided
Panel 1: The engine room of a starship, with giant cans of baked beans piped directly to the mouths of some heads poking out of the wall.
Panel 2: An outside view of the rear of the starship, showing an array of butts protruding from the starship, implied to be the butts of the people in the wall in Panel 1.
Panel 3: The starship captain issuing the command "fart".
Panel 4: The starship is now being propelled through space via the thrust generated by the array of farting butts from Panel 2.
This is more-or-less the same as the experimental drive introduced in Star Trek Discovery.
I love how the artist matched the skin tones of face and butts between the first two cells.