Twirl down the Scale property to expose the graph editor. Change the
keyframe type to Bezier. Adjust the KF handles to create a graph curve
that changes faster at the beginning and slower at the end of the zoom.
FWIW, until you adjust the KF handles, the zoom is proceeding at a
(mathematically) constant speed. The problem is that the constant speed
produces the illusion of going faster at the end.
Many thanks indeed Jeff. That looks like the doorway I need to be able to procede now. I'm grateful.
I do appreciate that mathermatically it is indeed already "correct". My two problems were 1) that I didn't know how to change said maths, and 2) that I'm an idiot!
Cheers, Eddie, too, for the link.
PS: Not speaking the lingo, I'm wondering what "FWIW" means, but I guess I'll work it out!
FWIW = for what it's worth.