You and Wiggles are doing SO well together! He's made really wonderful progress in target training, and it sounds like he's enjoying his exploration sessions.
I also have a couple of snakes that, while they aren't afraid of me at all and don't mind being in close proximity, simply prefer not to be handled. That's fine. I'm just happy that they trust me. I keep handling down to only necessary situations and even then I try to give them the option of maybe shifting to a container or climbing onto a pet bed, branch, etc. to be carried rather than held.