Thanks for the suggestion!
I could get to the same geometry to the kit setting, but the adjustments of shimming can be smaller than on just a plate setup on which you mount the ball stud - and it will keep the way of setting up the same as on a stock TRF201. Both valid reasons to me to go for turnbuckle blocks
If one doesn't consider that a problem though, indeed a tower consisting of just a plate is sufficient. I guess I'll find out if/when I look for a supplier of the alu blocks if the question of costs is of much importance here, because that could be a determining factor.