your idea is valid and technically it works, but you would need to define a second fake sat position so that e2 is not realizing that it is the same transponder. But for daily usage this is too complicated. Most of the time you need it not for 2 recordings but for watching and recording or pip and there service relation plugin and sd alternative channel is the easier solution.
Yes on satellite you can make fake postion - not so big thing to do, but maintenance can be little mess in log run.
As you sa not perfect, but should work some way if someone needs such solution.
In case of DVB-T2 I assume you cannot have multiple terrestrial*.xml files.
In general this CI handling is not perfect, as if you autorecord something on two CI channels & same transponder you can loose both recordings.
There will be more and more CI channels in future.
I think in long run it would be good to have tuner specific recording limit for CI encrypted channels.
Alternative service doesn't work in my case as I don't have SD available for those terrestrial channels.