They are all doable from the outside. IIRC the shift shaft seal is the lowest one, it would dump the most oil. A quart and a half leaves an awful large puddle.
There are 5 possible things to leak in that side of the case
1 -shift shaft seal
2 -Trans output (countershaft) seal
3 -neutral switch o-ring
4 -shift fork bar plugs (2 of those)
Degrease, clean, dry and inspect.
you don't have to split the case to replace the seal behind the sprocket.
also look at the shift shaft seal below it, It can be replaced from the outside too
I owned a 73 Buick Gran Sport that came factory with a M22 fine spline so long ago I sold it because I couldn't afford to put a clutch in it
But, yes, that is a very good analogy.
Very much easier when the engine is off.
and
Since I never find myself in traffic at a stop light, I never have the need to find neutral while it is running.
The Raptor 250 and 2012 carbed YFZ use the same throttle and cap. Although mine measures 1 1/4 between the the bolts on the right side and 2" give or take on the other 2 dimensions.