I've attempted to post about this before to little success, but I thought why not try again! I'm having a bit of an ork flag issue with my own personal mod (sadly not releasable publicly due to the whole GW rules thing) for DC, but it's a bit more advanced and weird than what one would normally expect. What I've done is used a hex editor to change the race information inside the strategic point, so the flags are being pointed onto the right races--but just aren't colouring.
I'll show some images to show what's happening a bit more:
The Chosen (necron_race) get their flag just fine, although it doesn't have any remappable parts on it anyway so it's trivial here.
The Harlequins (wb_harlequin_race) get the Chaos flag as they should... but it is always an Alpha Legion flag no matter what the army painter colours are
Free Botae (free_botae_race) have the classic Ork flag bug, without an existing flag given to them (as I wanted them to have ork anyway) and as this was the most recent race I kinda gave up on this issue by that stage.
But surprisingly, The Forces of Tomorrow (tomor_race) have the Imperial Guard flag which just works perfectly.
The Teal Empire (tealrace) have the Tau flag, as they should, but it has the problem of not recolouring or changing to the appropriate banner.
Any advice that you can give would be greatly appricated. I have tried to use the objective points mod flags, but they have the same problem as the stock DC ones do.