IMO, the site was always too complicated as there are too many top level headings, and many of those include child boards. The KISS principle always suited me. But that's just me. IMO. Create as many topics as you need to help you. But keep in mind not everyone shares your forum architectural choices. My choice for web development/format/layout is cater to the lowest common denominator. Something the www has forgotten over time.
As you can see SI, if I were to allow threads to meander all over, at some point we may be talking about catfish in the tropics. Someone reading this thread on the outside may look at it and scratch their head 🤔 thinking ‘ I thought I was looking at a topic on hypnagogia! This guy has lost his marbles. I didn’t know he’d end up talking about the speckles on cat fish, in tropic waters.’
As far as "splitting" topics, and/or taking a response and pasting it into a new topic.
I'm a data guy. I've worked with databases for > 22 years. I despise redundancy. That takes precedence over a single persons take on structural organization.
Also, there have been times where I've found one of my posts on another thread, and while it may be relevant, it is often taken to a different direction and often out of context.
Do what thou wilt.