Definitely possible. Tick rate isn't the problem, Elixir is very performant. Just the predictive elements are an issue if you're working with 2 different languages. I'd go with Gleam from the start and look into compiling to js.
Don't you lose a lot of the niceties of Elixir when switching to Gleam, just because Gleam is a younger project? LiveView would be the big one I'm thinking of. Do you see that as a worthy trade?
Cool! I'm going to have to look more into Gleam. I saw it hit v1.0.0 on ElixirForum last month, but I figured it was an alternative to Elixir rather than something that played so nicely with it.