Or am i worng?
I present you here some data, firstly all tough the bravery bonus you can get from running first on r1 and then elite its good (cuz you can double on it) i think they pale in comparrison to the +100% for the 1st playtrough, Here's a higher xp quest without 1st time against a lower xp quest with 1st runtime.
Which becomes way worst when you run R1 and EE Back to Back cuz daily playtrough and Ransack(More on Ransack at the end), Showed by this image
And to prove that EE and ER1 are SO CLOSE you shouldnt run R1 solo unless you have 100% confidence you can pull it out, specialy cuz you'll die and lose the 10% bonus from not dying (Which i with 10 reaper points cannot) here it is "Servants of the overlord" + "Spinner of shadows" epic life first playtrough, diference betwen EE and ER1. ON spinner itself assuming you die once its only a 9k diference in exp, with 0 diference in favor and A LOT of diferente in time(xp/h) if you're running SOLO.
If you're a new player like me, Avoid spending 30min inside a solo r1 you MIGHT finish and go for EE (SPECIALY Sagas) you'll 100% get more xp/h. But if you get a group, sure, rock that r1.
HOWEVER, if you can destroy R1 i 100% agree that you should run 1-2 days later the same quest on EE, but why 1-2 days and not back to back you may ask? ransack its now applying to epics just as heroics, proof below. And i cannot say if its 1 or 2 days cuz /ransack also doenst point that out for you, proof below also.