You don't need to open a new sheet set, and import the sheets.
Let's say you have a sheet set (.dst) that has a set up like this: (A simple example)
Code:
01 -- Cover
02 -- Notes
03 -- Project Layout 1
04 -- Project Layout 2
05 -- P & P Sheet 1 of 4
06 -- P & P Sheet 2 of 4
07 -- P & P Sheet 3 of 4
08 -- P & P Sheet 4 of 4
09 -- Details 1
10 -- Details 2
11 -- Plat
12 -- Agency Sig Page
So you create this one time.
Many of these never need to change filename (presumably 01, 02, 03, 04, 09, 10, 11, 12).
Sheets 05-08 can vary in name if need be.
When you get ready to work on the next project, copy the .dst and sheets 01, 02, 03, 04, 09, 10, 11, 12 into the new project folder. SSM will auto-relative path everything, so all you have to do is add sheets 05-08 as they are built for this job.
We did this for many years and never had an issue.