@mvpspl619 I would not recommend that you do this at all, honestly. But if you have the resources to try it and fix things that might possibly break, you could:
1. Use the plugin’s import feature to import the records into the plugin as object maps. You’d have to generate the JSON yourself, so you’d probably want to do some manual records and then export it to get the JSON structure, and then have some way of generating a matching set.
2. Then do some kind of update on the Salesforce records as you say.
Some caveats:
1. I’m not sure it would work. I think it would, but I’m not positive and would certainly not provide support for it on this forum, since it’s not a feature in the plugin.
2. Your initial question of doing an update on those records in Salesforce would not work. This plugin doesn’t catch update records unless they already exist as object maps.