KF21 is not low observable though... atleast not until future upgrades that they said would come after it enters service...
I know but has lower rcs compared to any other 4.5th gen platforms. The lower the better.
Truth be told any and all bases in bd can be compromised one way or the other.... hardened shelter and unconventional operations like the swedes is the way to go
Not all bases, there are few bases that is thankfully outside the reach of Indian MLRS range. IMO, BAF should concentrate on upgrading those.
For exmaple, Coxbazar airport which has been upgraded to BAF air base.
Similarly, Barishal airport should be upgraded.
Also, upcoming patuakhali airport should include BAF base.
Plus, they could also upgrade old patuakhali airport which is under Navy's control.
But these are for peacetime permanent basing.
For wartime, I think BAF must Adopt CONOPS similar to USAF agile combat employment. Using highways as runways to generate combat sorties.
In the end all fo BD is within India's ballistic and cruise missile range. And we simply don't have the resources to posses required numbers of air defense interceptors to outlast their missile stock. So, all permanent bases will destroyed or degraded.