IMO...
The PAF should call it a day and commit to 150 J-35s by 2040.
Forget PFX.
Just set a clear cut long-term requirement as-is, and focus the other resources on the economy and driving foreign currency gains to finance platform purchases.
Except for munitions, IMO, the indigenous production of air platforms is needless. It'd be best to leverage the limited resources to get good at AAM, SAM, SOW, ALCM, etc production. Set up parallel production lines, is indigenize more inputs, and be at a level where you can sustain a war effort.
If you have a strong economy, someone will sell you what you need re: platforms. An Indo-Pak War wouldn't last more than a few weeks, so the idea of having domestic fighter production makes no sense. Best case, you'll make 1 jet in war, and worst case, they'll destroy our assembly plant.
The platforms you get are in peacetime; in wartime, munitions and having as many available launch platforms as possible matters more (read: leverage UCAV).
So, if there needs to be an indigenous air platform, then make it a 2-3-ton UCAV. A comparatively simpler LO design (versus an NGFA) with a goal of having multiple final assembly lines so that we can roll a dozen a week at full capacity.
Those UCAVs are going to play a bigger role as strike assets (especially in high risk engagements) in a war, and being able to replace lost units rapidly would be key.
This is closer to what our industry can reach or realistically aspire to. We can even export them at a potentially good margin too.