Do I need to import as optimized media in order to export my final product as optimized media?

Hello FCPX community!

Please let me know if my thinking is correct here:

When I upload footage as original and proxy, that means I can see the project in one of those two codec as I am editing. When I export the end-result as Apple Pro Res 422 or higher, the exported project will be viewable as optimized media.

I do not need to import as optimized media in order to export as optimized media. Importing as optimized media only allows me to see the project as optimized media as I am editing.

Am I correct?

I uploaded a bunch of footage into my project as original and proxy, and the project is now near complete. The problem here is that if I do need to transcode everything a optimized media, it is a lot of footage and will take a long time because I recorded in 4k several hour of footage. I have an older Mac here at work...

Thank you for your time.