open work permit?

[matthewc]

so if you are being sponsored as a spouse, inland,
you should send your OWP application together with the sponsorship/pr application...

Yes.

what about your visa extension application?
should this be sent together or separately?

There's no need to extend your status separately. Applying for the OWP at the same time as the inland PR app automatically extends your status until they give you the OWP.

However, usually inland is not the best option. So if you're thinking of being sponsored inland, you need to really read up and ask yourself if it's actually what you want to do. It usually takes much longer, and there's no right of appeal.