I’d rather have it as it is now with both races the same day.
Drivers jumping between series is only a novelty and to make wholesale changes in an attempt to benefit a few, that may or may not actually race, IMO is not beneficial.
If you mean novelty in the sense that it only happens a few times a year, then I agree--and it should. But if you mean novelty in the sense of gimmick, then I'm not sure I agree. I think "specialization," so to speak, is pretty new. Mario Andretti, for instance, won F1, Indy, and Daytona. AJ Foyt won Indy and Daytona. Heck, Indy even used to be on the F1 calendar--as it should be.