Hi Adam,
Good to hear that you're considering the Fremo N-Re standards. I've been to a lot of meetings with modules built according to that standard and the technical part always works. Boosters might not be required if you make sure to follow the standards. It all depends on how many locos, size of the layout and so on. If you do need boosters make sure that you get a booster that has been tested and proven to work in Fremo meetings. Personally I have this one that just works as a charm;-) https://jokaelec.de/de/booster/booster-bo3500-bausatz.html
Cheers
Niels