Aggregate time limits?

Hi. I'm not really interested on the number of hours my daughter spends on each her phone or her tablet, but on her TOTAL screen time. Having separate time settings for each device is counterintuitive, she finishes her phone time and just moves to the tablet to do the same thing. Any idea when something like this can be implemented? I saw a forum post from almost five months ago stating this will be prioritized. Thank you.