Before suggesting them, please understand I am not interested in Dancer, Dancer2, Mojolicious, Catalyst, Moose, etc. or other heavy-duty frameworks

I totally understand that - I am exactly the same...

However, the wisdom of the Monastery suggested a framework or templating system to me. Like you, I discounted Dancer2, Mojolicious and the like but I am VERY pleased I took the time to try out Template. It didn't take long to make it work better than any of the CGI::* modules as it is not a huge learning curve.

Adopting Template has been revolutionary for me. I now hate maintaining the web code I wrote previously. Separating the logic from the display makes maintenance so much easier, debugging a lot simpler and development quicker. There's no way I would go back and I strongly suggest you give it a go. There is plenty of support her in the Monastery to help you master Template or an alternative templating system.