I find it a tad weird to have a custom title screen for an episode when the title screen asks you to select which episode you would like to play. If two episodes were trying to compete for that spot, that'd be a bit messy, so, launcher pages!
(The alternative is one SMBX installation per episode, but that's also a bit bloaty once people start doing that en masse, so we don't really recommend it. It's standard (intended) practice to only upload the episode folder (i.e. what will go into the worlds folder of someone else's installation) if possible, when releasing your episode.)
One thing which isn't quite the same as this but which serves a similar purpose: You can do some lua trickery to auto-load into a specific level in your episode, and if you're cheeky you can transform that level into your own custom title screen from which to load elsewhere (using more lua trickery, building your own title screen menu and such). One caveat to this approach at the moment is that save file selection happens on the launcher, but I believe there are some ideas to make title screens like that more easy to develop for the future.