The SCM T130 has 3,000 4,500 6,000 7,000 and 10,000. The adjustable groover in it can run at 9,000 RPM. I ran it at 7,000 to cut some tennons. 10,000 being too high it looks like putting the belt on to a different pulley would give more speeds. The belt would run at an angle and rub on the pulley outside edges but not sure thats a big deal. A shorter belt would be used. Not worth it to readjust the tension device but Just have a belt that is a few inches shorter. RPM could be calculated from pulley size. IF it goes up from 7 to 10,000 RPM on the top pulley, next pulley down being 7,000 then if it was on the top drive pulley and one one down on driven would be 8,500 RPM I think.
Anyone run a belt to a position to either side of where it should be to get more speeds. Ive had machines before where pulley alignment was well out and they worked fine. Cog belt on the machine now and so far my favorite type for the least resistance and likely be more forgiving.