Yes, to the amount of Footage.
Well, if you truly are only going to SD Tape and web then I would edit in an SD sequence.
You’ll be able to move the HD material around and re-frame all you want.
However, the HD is Progressive.
Drop a SD clip in a new sequence and let FCP match it.
Next delete the clip back out.
You can make you SD stuff Anamorphic easy enough in FCP. Check the box in the browser. Change the clips b/4 putting back in sequence.

Next drop in a 1080 clip with some motion in it and render it.
See how it looks. It might be fine due to the 29.97
When the edit is done, change the compressor to prores422 and fully render all and export using current settings.
Take that file into your compression program to make the deliverables.
Chris Tompkins
Video Atlanta LLC