Have you attached a seating arrangement on top ?Made myself one with a cheap multi position ladder ,nice and stable and folds up to fit in the truck easily.
And a steering axle to get it in place....A bit of chain and a padlock is worth adding alongside the ratchet strap.

You're obviously spoilt for choice with nice straight mature trees to put a highseat up against. All mine are in a hedgerow or woodland without a single vertical tree and so need a support to push them away from the trunk and with a decent back rest, otherwise you'd either topple out backwards or bent over by the tree leaning into the seatAs an example my tree seats are made with an open back also far shorter (depth wise) in the seat area then use the tree as the back rest.
@needsy
The picture of the tyre shows how the seat sits on the radius of a tree with a couple of straps.
Nice and light.
View attachment 352589
View attachment 352590
Yes I’ve got 2 ratchet straps, the rear section(feet) of the ladder hold onto the tree. It’s actually really stableI used an angled folding ladder and plastic school chair plus homemade rail. I rely on the gap between the feet of the ladder and a tensioned ratchet strap to stop any sideways movement, rotation or slippage. This appears to be what Needsy is doing. At 16 stone I've never felt unsafe in it. I tend to put another ratchet strap at the midway point on the ladder, but its probably surplus to requirements .
Ion
My seats are hinged at the ladder so when I am not spoilt for choice and the tree is leaning then I pack the basket/seat frameYou're obviously spoilt for choice with nice straight mature trees to put a highseat up against. All mine are in a hedgerow or woodland without a single vertical tree and so need a support to push them away from the trunk and with a decent back rest, otherwise you'd either topple out backwards or bent over by the tree leaning into the seat![]()

I’ve used red oxide and olive green spray paint out of Halfords in an orange tin it’s cheap tooWhat's the best and most durable paint for aluminium? (Assume it needs priming first)