Short answer yes, but a few questions to make sure that's the best approach...
I made the installer to make it easy for the user and be the "proper" Windows way - executable in program files, data in another shared folder, user created files in documents, etc. It adds to the Start menu and even assigns file types. In practice though I think people are concerned about security with an app that wants those permissions. Is that your reservation with it?
The Steam release however has a different folder structure - something more friendly to being run off a thumb drive.
Itch has its own Steam-like app for managing software that Campaign Manager doesn't currently support, but it could. Would that be your ideal?
Or is it you really need to have it on a thumb drive / something portable? Out of curiosity, what is that use-case?
Thanks!