You have concerns on possible actions if some players switch groups and you propose a solution that affects all players, regardless of how they play. As rbg_astro says, the DDA covers all this from the perspective of FD.
Seonid, Astro thanks for your feedback.
@seonid:
The solution I propose does indeed affect all players, as does any good/honest ruleset for that matter, and so does FD's own solution. So again, I respect the choice of game mode, I just prefer the rules to be the same for all at all times. So with everyone having a choice, and not "à la carte" (most suitable) ruleset according to the mindset or situation of the moment.
If with DDA, you are referring to:
http://forums.frontier.co.uk/showthread.php?t=6300
Then this is the original source for my concern.
As I understand it from that thread:
1. switching groups is possible at any time:
- They can change this option at any time
2. "ignoring" people impacts chances of encountering them ingame

eople on
others ignore lists will not be favoured if a choice exists when match making players together
@astro:
If I understand the design correctly, this opens the door for the exploit mentioned above. Especially given the fact multiple persons in this thread openly voice their intended usage (which is quite normal since it is designed this way), albeit in vague terms.
I don't see this being mitigated in the thread you mention and which i did study before posting (maybe I'm referring to the wrong thread?).