I'm a big supporter of using a humidity dome/plastic wrap and a heat mat while the seeds germinate. It speeds up germination and gives you a better germination rate. A big plus! Seedlings need lots of air and light, and keeping the humidity dome on reduces both of that and can be too wet of an environment for the tender plants. A heat mat can burn plant roots, make plants grow faster than they can support themselves, and make more fungal issues on the soil (too much moisture also plays a factor)