On scan page add a checkbox that will save logs of each scan check.
Save one(or multiple) logs and create a way to view(delete also) the log.
If multiple logs are going to be saved show a list of current logs and allow user to view or delete it.
Saving location: wp-content/pcp-files

Log could be something like:
General checks
Running PHPCS checks
0 errors found in file xxxxx
1 error found in file yyyyy

Performance checks
Running WP Query Params checks
Query xxxx must ....
Query yyy is ok

This will help on:
Easy save/send report by user later maybe sharing it later
Debug any issue that will stop the scan on any step