fps cap with in game limiter, RTSS and Nvidia control panel

Hi ,I have 2 questions

1.can limiting fps hurt a gpu?(i know its a silly question but i need to prove it to someone)

2.which one of frame limit options is better ? i usually use RTSS or in game limiter (if exists) but one time i used Nvidia frame limiter in control panel and i saw my gpu core clock came down to 1200 (normally it's 1875)but performance was like usual and i thought it might be bad for gpu and stopped using it

:)