Non-powerpoint magic for Savage worlds

I know there is already a few different non-power point magic systems. But This is one I want to try out in a game in the near future. This would be lower magic setting. Where magic has some risk but is not entirely dangerous.

Instead of paying power points to caste a spell or fuel a power instead the character has a track much like a damage track. This is some form of inner focus that could be linked to an attribute or something, Still just in the idea phase.

Each time a spell is cast a box or bubble is filled in, each set of boxes carries over to another set down the track. Each set has a casting penalty to it. that applies to future cast rolls. For example:

() () -1  () () -2   ( ) -3  {-4}

Any spell caste after the final bubble is filled in is at -4. And requires some kind of a roll (spirit maybe, Or vigor even) to keep from passing out from the strain. A roll of one on the casting die is a failure and the should result in some other ill effect. Maybe on a 1 the spell fails and two boxes are filled in.

Each box or bubble is refreshed over time. The time it would take would be based on how low of a magic setting that it gets used for. could be an hour, Or 8 hours of rest. Or days for extremely low magic setting.

The time it takes to refresh a box could be based not on the setting but also be based on the location. Maybe in low magic areas like wastlands or evil demi-planes mage refreshes slowly. While high magic areas it would refresh a lot faster.