Which Emsculpt protocol is better for building muscle?

both protocols build muscle so I don't think you should do Protocol #2 unless it is a buttocks treatment

I do not see a reason why you could not use Protocol one on the abdomen, even if you are thin. I do not expect that the EMSCULPT would remove too much of your remaining fat, if that is your question.
I would still recommend protocol two on the buttocks.

Thank you for your question. I don't believe there is a difference in the two protocols regarding how much muscle mass is increased. Some people do not tolerate the fat burning protocol if they are too muscular or too thin. Hence, they may not get the intensity up to 100% on the machine. That is probably the reason they used protocol 2. You can certainly request protocol 1. I don't know how your provider will respond to your request.
I hope this was helpful - Dr. Moore.

Emsculpt works by harnessing the power of high intensity focused electromagnetic energy. We use Protocol 1 on the device for patients who want a combination of fat burning and muscle building. The pulses are longer in Protocol 1 and cause more disruption of the adipocytes which can cause more fat loss. We use Protocol 2 for those who are relatively fit and want to be more toned. In our very fit patients, Protocol 1 can be a bit too intense and can become intolerable at the higher energy levels. To answer your question, what your tech did was probably correct without being able to assess you personally. As a side note, we never use Protocol 1 on the glutes, as fat elimination in this area can lead to an undesirable cosmetic outcome.