I'd avoid anywhere on the coast of Quintana Roo unless its somewhere along Costa Mujeres or Holbox or Isla Mujeres.
Xcaret is amazing for families if you don't mind all of the fake mayan BS and crazy prices. I'd hate to pay Xcaret prices and get sargazod like the photos below.
Yes, they have people to help clean the beaches but that isn't always possible.
You're planning during PEAK sargazo season, so I'd either look at the places I've provided above or the Pacific Coast of Mxico. We live here and it seems to be getting worse and worse every year. Usually we have almost nothing until April/May. This year were already at 1,300 tons and growing.
There will be people that tell you, "Don't worry, they clean it, Itll be fine." Take a look at the pictures and ask yourself "for the price is it worth it to take the risk?". They got sold the "don't worry, they clean it" and look what it earned them.
We live here and id be sper suspect on anywhere in QRoo from now until probs end of October.


"I've lived through some terrible things in my life, some of which have actually happened."
Mark Twain