And he will have to apply for the work permit from "outside" Canada - through the embassy that represents his country - once/if he gets a positive LMO and job offer. Keep in mind that it's possible for the embassy to refuse the work permit based on the permanent resident applicant not being able to demonstrate that he intends to return home at the end of his authorized stay. My daughter was refused a study permit on those grounds - after we were already in Canada, and being sponsored for permanent status by my husband via the outland process.
That being said, unless the overseas embassy has an extraordinarily long processing timeline, it is still better to apply outland than inland for several reasons - the most important of which is that the option for an open work permit with the inland application does not even become available until after the application is assessed for first stage. That is currently taking at least 11 months. Check the
outland processing times because it's possible that his overseas embassy could finalize a spousal sponsorship ap (allowing him to work as a PR) within that timeframe, and then the inland process is pointless. It's really only advantageous when someone
already has a restricted work or study permit because filing an extension to that permit along with the inland PR ap allows the applicant to continue working under the original permit until first stage approval, when the new
open work permit is issued.
Applying inland as a means of getting an open work permit doesn't really work. It causes the inland applicant to be, basically, stuck in Canada for up to a year without being able to work at all, while most overseas embassies will actually finalize spousal PR aps in the same amount of time, or even less. If you're sponsoring your "boyfriend" as a common-law partner, he may already have been in Canada for over a year without being able to work. Applying inland only extends that for at least another year - when the outland process allows him to remain in Canada as he is, and probably gives him PR earlier.