The Endura paper was changed in 2 steps that increased green speed and therefore required just a bit more magenta filtration. So, there are 3 batches of Endura papers out there that stepwise move upwards in filter pack.
This was done to make the improvements noted in the post above. It also changed some printer slope adjustments due to improved reciprocity failure IIRC.
Yes, R&D on color paper proceeds. Although the man behind the latest work is no longer in the division, there are still good people working to improve color paper.
I use about the same exposure for an 8x10 color print (with filter pack) that I use for a grade 2 print from a normal negative on Polycontrast IV or Multigrade IV. It is usually within a stop on my Beseler 45s Dichro either way depending on negative and pack.