To use 100% certification you will need to be qualified for accelerating decompression.
I qualified many years ago. When I first moved to 'technical' qualifications, none of the mainstream diving organisation qualified you for anything other than air (unlike now). Because I held a BSAC qualification, I was qualified to carryout decompression dives (on Air).
I followed my BSAC qualifications with my first technical qualification which was IANTD Advanced Nitrox - limiting me to 50% O2.
I followed this with a BSAC ERD, which limited me to 80% (later they moved this to 100%). I was also an ERD Instructor (previously a Nitrox Instructor).
I followed this with TDI Trimix, there was only the one qualification, no gas limitation, no depth limitations. Technically, this was the first qualification that allowed access to 100% O2. (Although as I say the ERD limitation was modified to 100%).
Basically, with the current courses you are looking at an ADP (Advanced Decompression Procedures) qualification to allow access to 100% O2. Although there are now so many agencies I stopped trying to keep track of what qualifications are available, and what limitations each has.
Gareth