Use rebirth only when the next run clearly speeds up
Follow the official train-cut-sell-upgrade-rebirth loop first: train Strength, cut grass, sell loot, buy the next cutter or upgrade, then use offline check-in guidance before deciding whether rebirth makes the next cycle faster.
For +1 Cut Grass Adventure rebirth guide and Cut Grass Adventure offline earnings, check the visible loop first, then decide whether offline gains and a rebirth move you to the next checkpoint faster than one more active grind.