LO I find interesting that there seems to be the capacity to ensure the USMC can declare IOC with TR1 Hardware and 2B software at +/- the same time that the USAF declares IOC with TR2 Hardware and 3I software. With both of these configurations giving very much the same capability.
It is unclear to me if this means that all the presently available F35A's are to be upgraded to TR2 hardware to then have 3I installed or only new build aircraft when TR2 Hardware is available will be part of the IOC. Could get interesting in the training pipeline with the different software versions, yes I do know the simulator arguments.
It does make 3I a far more important software version than as I perceive it it was initially intended to be....