Adjustable friction loop on small bungee cord

I used a few common friction hitches to make adjustable loops for small diameter (2-3 mm) elastic cord, but most of them grab the standing part too aggressively, to a point of stripping the sheath. Lesser versions of the friction hitches with e.g. one wrap don’t hold too well. Any ideas what may work well for such application?

I feel things are decidedly slanted the wrong way in this chase.
My cheat is to use shorter eyed elastic to adjustable section of more workable rope for an adjustable , even tho perhaps hybrid build. May old elastic in half to shorten and tighten.
1 place is around mailbox at street for outgoing packages of various sizes to be picked up, but can use linearly as well. Can use for small shock absorb and keep some tension in system too.

I don’t typically use the HFP Slippery 8 Loop on bungee cord, but I tried it and it seems to work well enough. Your results may vary depending on what you have.

https://notableknotindex.webs.com/slippery8.html