Building roundwood arbors - joining techniques & prep

I've been wanting to build some arbors for my garden gates to serve as both the gates and trellis structures for hardy kiwi and passion flower. I just happened upon an opportunity to get a bunch of black locust posts, so the time is now! Or maybe not... I know I'll want to strip the bark before building, do I need to wait some amount of time (a year?) after I strip them, before I can build with them? I know locust is pretty special in terms of strength and rot resistance, but I didn't know if it was special enough to skip that step.

Second question... what method of joining would be best for an arbor like the example below (apologies for the bad AI, I found it on Pinterest)? Should I be protecting the cut tops somehow since there won't be a roof overhead? Kiwi vines can get pretty heavy, so I want to be sure it is sturdy and not just nice to look at. I'll also likely be building some sort of arbor or pergola to support some grapes in my woods that collapsed the trees they were climbing on. The base of one of the grape vines is massive, maybe 6 inches in diameter. I'm sure I'll need to prune it back a lot to train it onto the replacement structure, but whatever I build will need to carry a lot of weight.

I built a roundwood woodshed last year of similar scope, to try out approaches.
I followed ideas from https://www.youtube.com/@KrisHarbour
on how to layout joints for curving pieces; it worked fairly well.
I cut lap joints at the tops of the main posts, with natural forks as knee braces.
On a different thread I read an expert writing that knee braces are not necessary, but they certainly stiffened my structure.
The post ends are under a metal roof so I did not attempt preservation beyond linseed oil.
I used timbers end-to-end through the concrete block holes, and recycled cabling,  to use the weight of the firewood load to anchor the structure and roof to the ground.
It has come through its first winter fine.

My next project is actually a honeysuckle arbour.
cheers Doug