If you use homebrew software on your Nintendo Switch you are extremely likely to receive a console ban and not be able to access Nintendo's servers with your Switch ever again. Although homebrew software can be used for many things it is most well-known for piracy which is why if you install it and then go online Nintendo is extremely likely to ban your console. Nintendo doesn't care if you use the homebrew software for piracy or not either. If they detect custom firmware or homebrew software on your Switch you will receive a ban.