Limit total training volume per week

In general, I am able to train any day of the week so I put in my availability as something like 1h for M-F and 2h for each weekend day. The result is that JOIN will often schedule 7+ hours of training per week. In reality, I would like to limit the total weekly volume to something like 5h but still make clear that I am available to train on any day of the week. My only way to limit to 5 now is to artificially set my availability to 0 for some days, but that may be suboptimal for my training. I would like to have an ability to set my total weekly max training hours and let JOIN decide how best to schedule the training over the week.