If you are under level 200, it's technically never too late to wash a very little amount of HP. However, starting late might increase the cost of HP washing (By several billion mesos sometimes). Here's my favorite HP washing "tool" we love you shiyui https://royals.ms/forum/threads/hp-washing-calculator.111127/page-6#post-655680 Feel free to ask any further questions about washing or the calculator above