i have the exact same need. my problem is that the print doesn't stick to support well enough, the skin right above the support is always really bad, the infill tangle up and make a mess. but, if i adjust z distance too close then the support won't separate.
i've found a kind of hacky way to get the behavior i want due to how it's calculating the bridge.
1. set bridge skin support threshold to 99%
2. set the support horizontal expansion to -0.1mm
3. set the support interface horizontal expansion to -0.1mm
hope this helps.