Djozz you got to try it(you'll like it)... Most original domes enlarges die projection and lowers lux performance for 100%(cause we mostly have have 100% lux gain upon dedoming right?)
Pre-coolimator enlarges beam a bit(I think it is 100 % bigger) but it is not loosing so much on lux performance so with better lenses we could have bigger die projection without loosing lux.
Edit: When I look at this thread about new style XPL emitter I am pretty sure that silicone will decrease performance by 5% but dome will remain small. So it is better to have clear dedomed die + pre coolimator which will enlarge beam projection (equal performance as new style flat dome emitters but with 100% larger projection) But of course this should be desirable only in aspheric.
Only advantage I see with new flat dome emitters is that they will probably not have tint shifting issues.