Hi Sven
Although the turns will be protected at the highest speed speed category for which the procedure is designed, PANS-OPS Vol 1, Part II - Section 5, Chapter 1, Para. 1.4.6 does state:
1.4.6 Alternatively, the procedure may specify a maximum IAS for a particular segment without reference to
aircraft category. In any case, the pilot shall comply with the procedures and information depicted on instrument flight
charts and the appropriate flight parameters shown in Tables II-5-1-1 and II-5-1-2 to ensure that the aircraft remains in
the areas developed for obstacle clearance purposes.
The tables mentioned are those that state the maximum speeds so I would read that to mean you shall use the lowest figure of the two, which will be the 150kts in your case.