Top Z Distance Tree Supports

Guys ive been having good results with Tree supports when setting the Top Distance from .2 to .27 or .28 they hold well and just fall off… Now if i change from .20 layer height and drop to .16 or .12 is there a rule of thumb as this also changed the Top Z distance to .16 or .12 respectively. Anybody got any defacto changes they make when printing at the .16 or .12.
I know about PETG and Support filament but i run over 20 printers so cant really have that on them all :slight_smile: as they are a mix of A1 P1 and X1