[Madame Cholet]

Has anyone had experience of growing a  thornless loganberry up a tree

[Trillium]

Can't say I've tried it before, mostly because being part of the bush berry family, loganberries need full sun to grow best. The shade of a tree trunk just isn't going to give you the fruit you're hoping for. Nor is the soil against the trunk. Loganberries do best in rich moist soil and under a tree is the last place the plant will find its needs. If you need something to climb a tree, plant a clematis.

[solway cropper]

Has anyone had experience of growing a  thornless loganberry up a tree

But....you'll need a ladder to pick the fruit 

[Trillium]

There wouldn't be enough fruit to justify digging out the ladder.