Second Telescope: Maksutov Cassegrain vs Refractor
I have viewed through many telescopes over the years and in doing so have met many people like yourself. To suggest a F/12.5 Maksutov will satisfy you would be the equivalent of telling someone to dive into the deep end of a swimming pool without knowing if that person can swim.

If it's bang for buck that motivated your question I think you would get the most if you just explore the capabilities of the 3 inch refractor for a while. There is a lot to be seen with that telescope and you have barely scratched the surface. 

Some prefer electronic eyepieces. Have you seen what they are capable of doing? I viewed with eyepieces for fifty years before trying a Mallincam ten years ago. I haven't used an eyepieces for serious viewing since. 

Take a look at the NightSkiesNetwork. It is a group that regularly broadcasts their observing sessions. 

https://www.nightskiesnetwork.ca/about

I cannot think of any better advice for someone like yourself than to stick your toe in the water for a few seconds before jumping in.