Stop relying on Wikipedia for specs.
Look at the sheer size difference.
It's impossible to fit XF9 into AMCA, no matter what you do. You have to either completely redesign the engine or the airframe, and both are impossible. And if you redesign the engine, it will have to be called something else. And if you redesign AMCA to fit XF9, you will have to call it AHCA. AMCA will become the same size as Su-57 or F-22 then.
F414 is not built considering stealth specifications
XF9 is built specifically for stealth, that's why it's single stage for high and single stage low compression and other stages as per the norms for stealth, and bit longer, as that reduces the heat signature at exhaust.
Even if we agree that F414 will be perhaps used for AMCA as well. Then it would mean there is out of the box new technology or design marvel with the frame. Install a normal engine, smaller in size, light weight and leave the stealth on the frame. The frame will be longer at the exhaust site to overcome the high temperature exhaust.
Smaller aircraft (low RCS) + Longer exhaust outlet ( cooler the residue) ( s shape ducts)
And I don't understand why they want Ge F414 on everything. Even if they produce a new engine in a JV using Kabine core , i don't see it happening before 2030. They haven't finalized anything yet!!
They have the budget for AMCA's engine, but don't yet have a plan for it.
They don't have the budget for K10, but have a plan for it.
Catch 22.
Well if they have plan then budget should be allotted. That's common sense.
Or may be budget they require is way higher what can be allotted so they started with something which has no plan. Money goes no where
The IAF plans to buy 40 AMCA Mk1 with F414, 20 IOC and 20 FOC. Other than that, GTRE have 10 years to get an indigenous engine working for AMCA and become operational in 15 years.
IAF also had plans for LCA Mk1 and still the induction is not complete because everything got delayed.
MWF? It's just a modified LCA airframe. Why will they face problems there?
Problems is the delay which is ought to happen. I don't see it coming before 2029.
XF9 is a 15+ tons engine. Probably more (18T ?) so not fitted for your AMCA.
The point is about their approach, of course it can't be fitted it's long very long. But it's for stealth, unlike Indian planning to use F414 ( non stealth engine) on AMCA. Or co develop with Kaveri engine technology which is still without plan.