Well honestly my idea for new TRs would be:
Heroic TR - like it is now - no loose of EDs or anything with them.
Epic TR - TR to lvl 20, loose of xp only in active ED - and thats why past life from the active ED.
20-28 is still a lot of XP.
And anything that makes you loose all EDs is just not fun...
And actually loosing all doesnt make sense. I mean - TR is getting rid of old life and starting new life. OK. But your "current life" is active ED I guess... not all EDs.