QSC8.3 CM554 CAPS - How to get .xcal file

[J99]

Trying to reflash now with CT 5.16 (after uploading the .xcal file from the ECM, which worked OK, trying to reflash with it back), the reflash fails after around 6 seconds with message "BDS Header Record is missing in cal file. [PDL Err Code = 6 ]" in the log file.

This looks a lot like what happened here : https://rawze.com/forums/showthread.php?...&pid=72137

So should I conclude the same with these older ECMs for QSC8.3 CM554, that I should look for Calterm 3.17 only ?
And get out of rom boot only via Insite ? (I have the official J91384.12 file from Cummins, but not compatible with my older Insite 7.5).

Any help here is welcome. Thanks.