Faster refactoring in Altium Designer 19: Quickly converting a circuit fragment to a new sub-sheet
No.  I'm not aware of a better way.

The only minor change I would make to your list is in Step 4:
4) Use Copy, then Smart Paste to convert net labels to ports on the new sheet.

Also, for step 5 you could use 'Create Sheet Symbol from sheet' to save you some mouse clicks.

This results in a new sheet symbol with the file parameter filled out, and all of the new sheets entries already inserted.

Good luck!