Edge Loop Length Tool is a script for 3ds Max developed by PolyHertz which lets you copy/paste or unify the length of a selection.
Its main purpose is to help you clean up messy or hastily made topology with a variety of options, allowing it to fit into various kinds of workflows.
The script can be used on multiple edges, edge loops, vertices, or objects. Both Editable Poly and the Edit Poly modifier are supported, and it has been tested to work in 3ds Max 2013-2021.
You can get this script for just US$4 here.