From PowerShell/vscode-powershell#1458 (comment).

We've implemented syntax/AST-based folding in the PowerShell extension, but the folding ranges it designates must be labelled with a FoldingRangeKind.

Region was chosen for syntax folds, since (for example) an if-block is not a Comment or an Import. But this means using "(Un)fold All Regions" toggles syntax-based folding as well, when a user might only want to fold explicit #regions.

Our current prospective solution is to assign a FoldingRangeKind of -1 or similar (which seems to work). But naturally that's not an ideal solution.

Is there currently a supported way of distinguishing #region folding ranges from custom syntactic folding ranges?'

(Also, I imagine that adding new enum values into FoldingRangeKind to cater to increasingly granular folding ranges would be infeasible -- just more an illustration of our current workaround.)