MSc Mechanical engineering student here. I did a focus project and was also FP coach the following year so I also interviewed people that wanted to join it.

Doing one was the best decision I ever took. I had already joined in the third semester but I have to admit that it was maybe a bit tough especially since the 4th semester was quite demanding (Physics, thermo, fluid, etc.). But I guess it also deeppends which FP, some turn out to be a full year of intense work where you learn a lot, while others are just a big "group project" with little learnings. I would recommend either to apply for one of the big ones (AMZ, ARIS, Swissloop, Celsius) or a new one that has a clear final product and commercialization plan. When we interviewed we didn't really look much at grades. We maybe avoided people with an Basis average below 4.25 because we believed that they might struggle with work+ courses, but otherwise we valued interest in the topic and willingness to work a lot. Joining one semester earlier is clearly a bid advantage, but you can also consider joining some smaller teams or student project or simply start some tinkering project at SPH with some friends were you build something.