Keep in mind I followed the following method, but, I was mounting third party casters.
Not having any template, and knowing the proper positioning of the wheels when lowered(both positions - 1/4" And 1/2"
Cut those in half! 1/8" and 1/4" Nope! see post # 19 this thread!!! clearance to the floor), I slipped the casters onto the leg and clamped them while I 'adjusted' the caster location on the legs. Critical was the casters must NOT be supporting any weight when 'raised'. They may rest on the floor, but the upper end must have clearance so they 'float'. By locating them, then measuring the leg distances above the floor in the two lowered(casters lowered/ss raised) positions and the floating of the casters when raised(ss lowered) and doing so for both sides and ends, you can mark the hole locations. A sanity check to assure all are the same distance from the original holes, then drill.
If I got SS or BM casters now, I would do it the same way! i.e. no template!
No matter how you proceed, realize you will be splaying the legs slightly more than originally.
IIWM, I would not predrill the holes. Too much confusion surrounding those templates. Hopefully ss has gotten it correct by now! I would judge that before actually drilling.
Too many folks have stated they work correctly, but also said they needed to raise to the high position to clear the floor(by far less than 1/2"). SS is included in that 'group'.`
Age sure does mess with yer memory!!!! And sometimes it works correctly in spite of 'other stuff'.