I'd rather have two identical tyres on the front for both acceleration and deceleration!

Dunno. The standard advice is “best-tyres-on-the-back”, but that’s not much of a guide for where to put mismatching tyres.

This site

https://www.drivingtests.co.nz/roadcode-questions/car/theory

says to put it on the back for both FWD and RWD unless you have a limited slip differential, though the stated reason

:this is because the front of the car is used for steering, braking and acceleration and therefore it needs the best rubber at the front. taken literally, directly contradicts the standard best-tyres-on-the-back advice.

They also say “Never fit more than one space saver to a vehicle”. You aren’t very likely to have more than one space-saver, but if you did it would seem to get you around the mismatch problem, and in that case they should probably go on the front. I’d doubt the consequences of that would be too severe unless you are a really major idiot or very unlucky

Here’s what happens when you fit four space-savers to a high-performance vehicle and chuck it around a bit.

www.youtube.com/watch?v=HPh90yNX-mY

(Everyone within a 25 mile radius dies, obviously, but apart from that…no real problem)