I seem to recall this problem before. I scale up my tool at the lowest level then go up to the higher levels to find the detail is lost! If it is scaled down then the detail is really distorted.
So the question is… How the heck do I scale my model in zbrush along with all the subtools? 
i have this problem, too!
and i find out that you have to scale your model at the highest Subdiv Level!
yeah thats what I had to do before. but this is impossible with lots of subtools!
One solution I’m thinking of is saving out displacement maps for all the tools, scaling everything in transpose master and then apply the maps. Though this would be a bit of a pain to do and there is always a loss of quality involved.
can anyone explain why the scaling does this? It’s a simular effect as when changing the values of a displacement map in maya.
ok that didn’t work so well… GREAT!! Anyone got a solution for this?? It’s quite a massive problem if you lose detail scaling your model… doesnt anybody think?
cheers spaceboy. he mentions this problem on the first page, but it doesnt seem to get resolved and the thread just seems to carry on focusing on that import/export scaling issue, which is a different matter altogether.
I have that same problem in zbrush 2022.0.5. Still no solutions? Scaling at highest subdivision could work, but not if you have multiple subtools and use transpose.