If these component instances are simple 'boxes', then they could be Scaled to resize them without recourse to make_unique for the affected instance.
BUT if there are details parallel to the direction of Scaling then they'll distort.
If the one tread is different it is unique ??
If the straight nosing is a separate nested component instance on the front of the tread, placed within the tread component itself, then having one unique tread that has a different rise will not affected the nested nosing components...
Edit any one of those nosing components... and all nosing should change to match across all tread instances.
To be realistic the change to two tread components is hardly onerous π
BUT the approach of nesting some common parts across different componnets, and scaling 'box' shaped parts could cover most bases ?
S