Updated App Screen Time limits cumulative?

I have seen posts from 2-3 years ago about this but I was hoping for a more recent assessment of the situation. I have set up app limits for my son with his apple id across 2 devices.

1) A limit for games overall

2)Another limit specifically for Robolx so I can make this less than overall game time occasionally if he is playing too much Roblox

3)Also time for social communication where he can message and call his friends.

I want these to be a cumulative time limit... but I am afraid what I have done is give him separate limits to hit and if he spreads time out across these 3 things it is way too much time. If for example, I have selected 1 hour for each rather than having 1 hour to split among these activities I have given him 3 hours of gaming and social to enjoy. Is this true? Is there a way to set these limits up as cumulative and still be able to adjust them separately?

Thank you!!!!

-A mom trying to navigate this complicated digital babysitting world!