Apply BME to Brown's PLME?

I’m applying to brown and I’d like to apply to the bioengineering department within brown. However, I want to apply to the Medical program there (PLME). The problem is that one of the essays requires me to talk about how I wish to integrate sciences and liberal arts, which doesn’t really compliment bioengineering.

The focus on the program is on “liberal arts,” so would they be unlikely to admit a candidate who selects bioengineering as their first choice?

No, PLME admits plenty of students who concentrate in engineering and other STEM fields.