There was no correlation between time to match start and value at the time of bet placement.
Flat profit might be a confusing term. I mean calculated with a flat staking plan, betting 1 unit on every bet (this removes the effect of staking strategy).
You’re right that you should always bet closer to match start if you have to choose. If you don’t turn over your entire bankroll each day, you should increase the time to match start filter.
Interesting last two questions, I’ll have to take a look!