Yes, I know the settings are centuries apart but I was curious if anyone has seen any Deathwatch house rules for incorporating Primaris marines? I have some ideas but it's difficult without starting them at higher XP equivalents since Adeptus Restartes are generally better in the fluff than Secondus marines in most comparisons. The XP system I think reflects the disparity well in that "normal" marines would get additional skills/traits/equipment to reflect their experience/renown whereas a newly inducted Primaris would have a boilerplate better starting point in terms of stats and basic equipment.
p.s. I'm a big fan of the basic primaris Mk X models (not so much the others) but am having difficulty incorporating the IMO needless changes to the fluff.