Previously you used to be able to rotate a negated part outside the object you intend to union and it would rotate the UV’s of that union to match the recently negated part. This is no longer possible in studio.
Expected behavior
A common technique for many years to fix UV direction on unions was to change the bounding box of the union. This was accomplished by adding a properly rotated part (often larger than your union) not touching the target then performing the boolean.
When performing this action, the boundary box is corrected but the UV’s are still broken.
