P: channel swap option

"I still think that the channel mixer integration in LRC and Camera Raw would make sense because in this case it is also a raw development step."

Using a creative profile that swaps the channels as described in @Sean McCormack's previous post is precisely "a raw development step" -- creative profiles get applied to raws before the other Develop settings are applied.

Capture Monkey have RedBlue Swap profiles

http://www.capturemonkey.com/redblueswap-lightroom-profiles

You can edit these for newer cameras using dcpTool. 

https://dcptool.sourceforge.net/Introduction.html

I don't know if you have played with the Calibration panel in LrC? Some fairly extreme hue shifts are possible and that operates on the input side in terms of RGB channels. So, easier to then work with than when extreme operations are applied via RGB curves of ToneCurve panel. That operates more on the output side (as a post-effect).

The use of some of the Basic panel adjustments can become quite non-intuitive when major shifting of hues is being applied..

@richardplondon
Thanks, I couldn't find this article. I had also tried the way via lut's, but then I was probably too dizzy.
Thanks again, but I still think that the channel mixer integration in LRC and Camera Raw would make sense because in this case it is also a raw development step.
Best regards Marko

A quick Google search found LUTs available towards doing this natively inside Lightroom Classic without needing to go to PS as a separate version. I can't vouch for this approach from personal experience, for infrared in particular, but have no reason to doubt it either. This sort of extreme processing may complicate or degrade on further adjustment - so there will still be some degree of trial and error needed, to work out the best workflow. 

Via LUTs all kinds of weird and wonderful things can be made accessible inside LrC as a 'black-box' effect, without LrC needing to provide detailed controls of those kinds. Photoshop is more the context for that. 

e.g. at this link

Updated Color Infrared LUTs v2 | Rob Shea Photography

it appears that a range of channel-wrangling operations may be workable.

credit: Rob Shea Photography.

Just to note, that webpage pre-dates an update of Lightroom Classic which made access to LUTs somewhat more straightforward, with the use of "creative" profiles and not only "calibration" profiles (which are camera specific).

As I understand it a suitable "creative" profile would be selectable inside LrC that refers to, and enacts, transforms that were recorded into a LUT.