The previously Paste special & distribute plugin are no longer maintained but are replaced by two separate plugins.
This one are Distribute Elevation plugin v1 .
Is accessible under Furniture->Distribute elevation or an icon on toolbar.
IMHO I think this plugin must be replaced by an missing option in main SH3D.
How it work and what use for:
Let say we have some stairs...
but is not quite what we want;
we know the maxim high and don't want to make more precise calculations so:
-select and elevate the last step to maximum high...
-select all stair steps and:
-this could be the result.
Are more close to what we call staircase.
RECOMMENDATION:
Remove PasteSpecialDistribute plugin.
While I'm not a programmer use it with care!