I don’t think either the website or the apps are support such use case.
E.g. the uspsa# is one of the shooter’s unique identifiers. I’d expect that app will create new entries when uspsa# is changed in the CSV file that is being imported.
The only case that is going to work is to complete your registration on the web site. Then instead of importing match registration to the app using your match pin# - you export registration CSV from the web site, edit uspsa# in there and then import that CSV file into a newly created match on a tablet as described at Importing shooter registration data into PractiScore app
Note that will be essentially a new match, not linked with the original registration on the web site. You will have to use “claim results” for your club after match results are posted to PractiScore web site.