It's not that - the shims are really small in diameter and the tool requires you to put it between the 2 buckets you're working on, while the cam has them open. then close the cam to give clearance to get the shims out. In reality the tool is invariable trapping one of the shims in situ - so... start again. this has to be done twelve times - did I mention TWELVE?
By comparison, the Suzuki (GS) tool was used while the valve was closed. the tool had a cam built into it so that, as you inserted it, it opened the valve so that the LARGER shim could be removed.
MUCH better!!
I think I have PTSD over this.
I used to do a few of my mates bikes. Kwakas were easy. Yammies were easy, Suzukis were easy. Hondas, including Bol d'Ors, were bastards!!