Someone else asked a similar question about gearing strategies, let me know if this reply helps out:
The current default healing strategy is Mythic+, designed with an emphasis on 5-man dungeons. For LFR, it should serve you well enough too.
In the next couple weeks, we will be adding some raid-specific healing gearing strategies before Uldir opens up that is designed more for larger raid groups. You could switch to that when it is available if LFR raids are the main place that you like to heal.
Custom strategies are mainly for people who want to do something very specific with their gear, or tune a strategy around very specific simulator settings. For the casual player, you’ll usually get worse results than one of the options we have crafted for you.