Yes, you may use proxies for editing then afterward in Premiere Pro relink to the original 4K video to save all the scaling work you made with the proxies. Here is how to go about it:
1. Create a new 1080p sequence in Premiere Pro using the 720p proxies you imported.
2. Choose Proxy > Attach Proxies by right-clicking on the 720p proxies in the Project window.
3. pick the “Ingest” option and then pick “Create Proxies” with the “ProRes Proxy” preset in the Attach Proxies dialog box. Your 720p proxies will be converted into editing-ready ProRes Proxy files using this technique.
4. Edit your video using the ProRes Proxy files in a 1080p sequence. It is feasible to alter with proxies and then connect back to the original 4K content.
5. Select all of the clips in your sequence and then use the right-click menu to relink to the original 4K footage. Reconnect Full Resolution Media by selecting “Proxy”.
6. Choose the folder holding your original 4K footage in the Relink Media dialog box, then click “OK”. All of the clips in your sequence will be relinked to the original 4K footage by Premiere Pro.
7. In order to keep the scaling you made with the proxies, go to the “Effect Controls” tab and modify the scale settings on your clips as necessary.
These procedures simplify transitioning from utilizing proxies to editing with the original 4K footage while maintaining all the quality.
By following these procedures, you may quickly transition from utilizing proxies to editing with the original 4K footage, and all of the scaling you did with the proxies will be preserved.