^^^^ I think, the crux of the issue is wrt
immediate disparity wrt fielded stealth-capability wrt our neighbours (with whom we have fought multiple wars),
in the 2030-35 time-frame.
The issue wrt falling sqn numbers is a long-term issue and there are several programs currently in progress (MK2) or even currently-in-proposal-stage (MRFA), to mitigate it. Either way, mitigating or not mitigating this long-term issue of falling sqn numbers, has no bearing on the short-term stealth-capability parity issue.
Yes, AMCA would have been the mitigating factor, but it
won't be available in 2030-35 time-frame, so a foreign solution (knee-jerk one, aren't we/IAF masters of that

) is required.
And, neither can Rafale (via MRFA) mitigate this disparity, despite all these wink-wink nudge-nudge comments all around. A 5th Gen platform will trump a 4.5 gen, eventually - more-so, when faced with such atrocious levels of numerical disparity between them.
That's the price to be paid, for vacillating to fund it, by approx 4-5 years - all for some mythical private-sector mfg capability.
(IIRC PDR completion was in 2015-16, whilst approval to proceed was in 2024 - even now the funding is limited to prototype-dev etc and, the all important, JV for a suitable Powerplant remains undecided)
So it boils down to
another emergency-purchase (sigh!!) of either Su-57 or F-35 - being emergency purchase etc, it shall
be limited to 2 sqns max.
Hopefully by now, you may have noticed, this scenario is an exact copy of M2K (or MiG-29) purchase of the late 80s - then it was to counter the latest-and-the-greatest F-16s, and now it's the J-20!!
(neither latest and not certainly the greatest, but still a fielded stealth platform, nevertheless)
But the
important difference between then and now, is that we
already have a successor program (AMCA) to this emergency-purchased stealth platform now, unlike nothing as such available back then.
So, there's
no need of creating any MKI variant of Su-57 (or F-35, will not be permitted anyway) etc,
nor is there any use case of domestically producing them (due to the on-off and limited quantity, nature of purchase).
It will have to be of direct import nature etc - maybe some MRO facility can be thrown in as a deal sweetener.
MoD can as well coin a "strategic capacity building" type of a tongue-twister gibberish, and soothe a few (very few) ruffled feathers. After all, there's no other import-pasand society than ours.
Of course, the most important question remains - even if that's what needs to be done, what exactly is the practical solution. I doubt F-35s will be made available and Su-57s are not exactly the stealth platforms that they have been advertised to be - but then again, neither are the J-20s (the principal adversary).
So IMVHO,
another emergency procurement is inevitable - will be uber costly yes, and thus limiting the numbers (to say max 2 Sqns), and the funds for it may have to partially come from the MRFA budget, limiting that number* as well.
Question remains, what can we
negotiate in exchange - for
Su-57 it will have to be full-ToT (whatever that means) for Izdeliya-30. No idea what could it be for the F-35s (if at all, made available, in the first place).
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* Assuming Rafale is the MRFA, betw whosoever said that 100 platform vol is an absolute must for any domestic production-line setup - OEM reps ofcourse will, it's their job afterall.
The price of Rafale (M) tells us, that domestic-ToT-based-production of such platforms unit-prices will not/can't be cheap - so nothing much to loose there as well.
Something like 57+26 (M) = 83 is also a good number for 10-12/year production rate - it can be increased, if OEM decides to shift some of other customers production vol to it. If not, the production-line can easily be transformed into a MRO facility.
And if Safran gets the AMCA TF jv, then a joint-domestic-production setup of the M88s (and the AMCA TF) can always be envisaged.