I did this. I went Feb 19-25, had DVC resort reservations, ADRS and FP+ reservations for 9 people all with separate
MDE accounts but all linked as family for this trip. Simulataneously I planned a 5 night april trip for just my family of 4, again with DVC resort, ADRs and FP+ ressies that needed to be booked while we were at WDW in February. All in all I'd say its fine - as fine as anything in MDE works
After an initial linking nightmare back in January for the 9 people that took essentially 6-8 hours of calls to the included family members, DVC and Mde tech support to finally insure it was all worked out everything was basically fine. The normal MDE glitches happened, but they happen no matter how many separate trips you have. I am talking about glitches like reservations disappearing for an hour but magically reappearing on their own when I checked later. I have experienced a few glitches, but nothing major where things actually disappeared and not with the frequency that some others have reported. In Feb no one in our party of 9 had a single problem with MBs unlocking rooms, park entry or FP+ access.
And my parents were two of the nine and at one point they had 5 resort stays with ADRs and FP+s ressies (they live in FL). She had 2 nights in Nov, another 1 night in Nov, New years Eve, a January 2 day and finally the February 7 day (she was there longer than me). They never had a single issue.
The one thing I would advise is to always double check what you are modifying. We have some favorites we hit every trip for ADRs. When you look at your full list of reservations, both trips come up, so just be sure if you have any repeats for the two trips you are modifying the correct date.