It's worth asking Monks which are more experts with Mojolicious whether it can indeed be run in this environment without privileges/access and how. If not, the CGI is not bad at all and will be fine. But do read some more on caveats and alternatives: CGI::Alternatives

I too operate a number of websites on shared hosting so feel your pain. For a long time I used CGI for processing input from a web form but never to generate the HTML.

However, I ran into a number of random errors that I could not debug. I suspect they were more to do with the hosting environment than the module. The result was I wrote my own code to deal with form and image uploads instead.