C&P Clips to New Timeline

Hello,

Must I reoptimize clips if/when I copy and paste them into a new timeline? It seems after I do this - primarily to fiddle around and experiment with an established version of a completed video - the new timeline overheats my system (a no frills MacBook Pro 13" 2019) a lot quicker. I am also viewing the clips on quarter resolution and both use of proxy and optimized media options are checked.

Any info or tips will help.

Best,

A. B

Am I really the only one experiencing this issue or perhaps I did not explain it correctly? Anyone else experiencing issues with copy and pasting full clips/videos onto a different timeline? Some of the fx do not transfer over to the second timeline. Also audio reverts to pre-fairlight conditions. By that I mean the work I do on Fairlight to audio clips do not fully transfer over to the new timeline, the most obvious is the color of the tracks, but also mono reverts to stereo, volume levels change, and audio fx are changed.