Yes, you can increase your spend after the 3-day optimization period without resetting the optimization. Pinterest's algorithm optimizes your campaign during the first few days, and after that, increasing the budget generally won't cause it to go back into the optimization phase. However, if you make significant changes (like drastically increasing the budget), it might trigger a minor adjustment period, but it won't fully restart the process. Starting with a lower spend like 5 is a good strategy to test performance before scaling up.