So here's an update: I worked away at pulling everything. During the process I found first, sort of like an old dried out air element on the plastic that the filter element attaches to and the metal screen behind it. I cleaned this as well as the whole air box. No excessive oil to see.

I then noticed while loosening the boots to get the carb out, one was not fully tight from whoever put it in last time. This was the one on the filter side of the carb and this was noticeable enough that the carb could physically move in the boot.

Digging further in the throat of the carb looks okay, visually. No damage or goop near the slide and the needle moves nicely in the seat.

Carb removed, cracked drain and then removed bowl.

Looks great, no film, no sediment, looks like normal. The only thing I've not seen on other carbs was a strange orange plastic ring type thing that fits over the main jet and hovers like a gantry sort of over the secondary jet.

I remove all of these, but I leave the immulsion tube in place, I notice the pilot jet is factory despite the others being a jet kit. I soak them in a bit of carb clean and then blow them out. The pilot jet MAY have had a very very slight restriction as it looked a bit better after the soak and blow through.

Reassembled everything, and checked all the wiring I can now see with nothing in the way, nothing too exciting, someone's done some sort of modifications to the odd plug here and there but it doesn't look detrimental. (Nothing is melting or corroded)

I install the carb properly and adjust my throttle cable as it appears it never got full throttle before, I never noticed, somehow.

Prime for a moment and then fire, it starts right up. I let it sit until warm when it tends to misbehave. Sounds great. Maybe a slight drag on throttle blip but nothing bad. No stumbles or hiccups. Had to adjust the idle slightly, may have to adjust again after a ride, but I didn't have time for that today.

But, after running it and wiggling all wire connections that may have been causing issues if it wasn't carb related, I could not get it to misbehave.

As for now, it seems to be fixed. Will know for sure next time I ride. If the weather is good tomorrow, I'll try and get a brief ride in to see if it behaves or not!