45 seconds is plenty.
get one timeout to use on a particularly complicated shot if needed.
Learn to look at the yardage when your ball stops rolling and already start doing the mental math on the shot before it's your turn. or if next, while the game is loading.
if slow on the mental math for whatever reason then play with a calculator beside you. Every phone has one now.
if you use 3rd party programs to calculate for you and you're losing time by entering the numbers and alt tabbing then that's on you. stop using that crap. learn to do it yourself. it's faster.
see the same thing as above if use spreadsheets and that's slowing you down. that's on you. not the game. learn to play without that crap.