This tactic works for the first few, but after that is no good. I honestly think the AI cheats on this mode since they can get ahead quite fast without using all the boosts.
You need to make the first boost earlier and get ahead of the pack. The ideal "range" would be around +4/+6 for the first boost. If the AI is boosting earlier, then +1/+2 is already a big help.
After you are ahead of the pack, then you can try maximizing.
The maximum zones you can jump is +8, so if you get +6,5 or +7,9, use the boost as the next one won't give you much of an advantage.
The best way to win is to maximize your energy( +8) and use it to finish the race. So, if the target is 30, then by zone 22 I am focusing on getting all the boosts I can to finish the race.