Look .. you claimed that GTRE is working on Al 31 the burden of proof lies with you .Multiple agencies have been reporting the current lot of 8 nos dry thrust version of the Kaveri TF is being mfgd by Godrej since 2022 & you're singing a different note out here .
For indigenization of the AL-31FP & up rating it which is what a part of Project Ganga is all about in keeping with the IAF SQRs for this TF , DRDO will have to be roped with GTRE playing the role of the lead integrator with other DRDO labs contributing & HAL functioning as the production agency.
If HAL were so competent as a development agency , we'd have developed indigenous FAs & various other vital components like the TF long ago.
Look at the progress of the HTFE. It was kicked off in ~ 2012-13 & was supposed to have been certified by 2022-23 . The date's now been pushed to 2030 & even that's not a certainty.
On my side I'm going by what each agency is actually working on .
"If HAL was so competent they would do x y" . How is that even relevant ? GTRE has been working on the Kaveri since the 80s.
HAL are the production partner for the al 31 , they know which parts need to be localised , what specs the parts need to have , they have the SOPs for testing the engines they produced .
Regardless .. get an actual official doc that GTRE is working on the al 31 or this entire line is utterly pointless.