One problem with most all the BB cup tools is when you have to apply massive force (to loosen the cup) and also keeping the tool engaged with the cup (as in not slipping off). I prefer to use a splined tool, compared to the outer ring/notched tool) because you can use a long lever arm (to the point of clamping the tool in a bench vice and turning the frame). To prevent the splines from disengaging during this effort some form of a clamp is needed to tighten the splined tool onto/into the cup. The simplest is to use the axle bolt and washers/spacers to bolt the splined tool against the cup.

Some Euro BBs have the plastic BB cups with both splines and outer notches. SKS, Thun amongst others, Andy.