I still believe that as a rich country we can afford two distinct types of fast jet. F35 for expeditionary participation with allies and Something else for Domestic tasks as I see the F35 as overkill for NORAD duties.
We need to make sure we are not pigeon holing ourselves with a single fleet of aircraft that are too expensive to operate and maintain. We are never going to be the lead bomb trucks entering hostile airspace by ourselves.
To me Gripen makes sense with local build and domestic support flying from forward bases in the north and along the coasts. F35 for the dazzle dazzle alongside allies.
Sure, Canada could potentially afford two completely different types of combat aircraft, but the question remains, "what advantages to Canada would a currently available fighter other than the F-35 have in post-2030 RCAF service?"
The only advantages some of the currently available fighters have is in initial acquisition and/or operating costs. My memory could be faulty here, but I seem to recall that in the latest production lot, the per aircraft price for the F-35 had dropped to below the per aircraft price of the EF2000 Typhoon. On doing a quick double check, the LRIP 11 lot was USD$89.2 mil. per F-35A and that can be expected to drop further once production transitions from low rate to full rate.
I see no real advantage to Canada doing a domestic build, since that would be expected to raise the per aircraft prices higher than purchasing from an already active production line, and any Canadian production would cease and the line and workers would become idle once the Canadian order was completed would almost certainly be within 5 years of the first Canadian production.
The last bit, operating 4th gen fighters from forward bases in the North and along the coasts seems to me like the expected threat scenario is one I consider unlikely, as it seems to centre on either performing interceptions of un-escorted hostile strike aircraft, or establishing local air superiority. For both scenarios, one has to consider who the expected adversary is which IMO would be Russia. Given the types and ranges of some of Russia's standoff munitions, along with where Russia has some of the northern air bases located, RCAF interception missions would either be only against already launched LACM's, or against sorties of strike aircraft with escorts. For the interceptions of already launched strike missiles, any RCAF fighters would not have to worry about being engaged by hostile air so 4th gen aircraft might be fine (then again, the sensor fusion of F-35's might be needed to detect, target and engage some of the newer missiles). However, failing to plan on having future RCAF 4th gen fighters operating in the North against hostile Russian air including Su-57, is IMO a failure to plan. I see no valid reason for Canada to operate fighter aircraft without giving the aircraft and pilots every advantage possible to win engagements. The LO features of the F-35 plus the sensor fusion should give Canadian pilots an information advantage in Situational Awareness in most circumstances. However, if a RCAF pilot was in a 4th or even 4.5 gen fighter and encountered Russian Su-57 aircraft, then most likely the advantages would lie with the Russia fighters, and therefore the Russian fighters would be more likely to win such an engagement.