If you have documented temporary status in Canada that's currently valid, you should have included an
extension application WITH the PR application to protect that status. In doing so, you choose what type of status you request. It's my understanding that you cannot earn an income in Canada (whether that be by working for someone else or starting your own business) without having a work permit. So, if you want to start your own business, you need an open work permit. Had you included an extension/change my conditions application WITH the inland PR application and opted for the "initial work permit", you would have been issued the OWP after first stage approval and you could start your own business. If you have documented status that's still valid, send your extension application NOW to CPC-Vegreville so that it's received by them before your status expires. Include a cover letter that tells them that you have an inland PR ap to match the extension application to - write across the top of the extension ap, "INLAND PR APPLICATION - DO NOT PROCESS UNTIL FIRST STAGE APPROVAL". You do this because you are not eligible for an open work permit without the inland PR ap and the first stage assessment - so you want them to match the extension to the PR ap, and not assess the extension until they've assessed you as an eligible PR applicant.
There's no guarantee that they'll actually match the two, but if you get your OWP ap in to them before your current status expires, you're at least protecting your temporary status until after first stage approval. Chances are, though, that they'll match the two and issue you the OWP after first stage approval.