They have plenty of fantastic Greenbacks, G12H, Classic Lead 80, and Mesa Black Shadow (Cali IV) speakers.
I hope to see them shot in a 4x12 cab because openback and small 1x12 cabs don't do justice to these speakers.
Also, each speaker in a 4x12 cab sounds different and the axial direction you capture it matters too, I hope to see more of the Greenback 25, 20, 12H and Match 25 speakers in a 4x12, and the Brit V30 needs another attempt it's godawful.
Line 6 can do a LOT with what they already have, just choose the good sounding speaker (or two) from that cab, and move the 1x12 Celestions to a proper 4x12 for capturing.
* Disconnect the other 3 speakers terminals if you are capturing one different 'implant' speaker in that 4x12 to not add coloration from the other speakers, and never leave speaker holes open, the cab needs to be air tight.
This is my advice, and again Line 6 can do A LOT more with what they already have by moving stuff around.