Removing they engine wont take much longer, and you get to inspect everything, lap the valves, and grease the swingarm bearings aswell.

Id do it "properly" or wait it out untill you feel you have the time to remove the motor.

I think the time consumed is about the same, as you will struggle way more with the engine in frame. Not much room to work with, and hard not to contaminate stuff because you struggle with the parts. A small chip of paint, a bit of dirt, or heaven forbid a lost bolt will play havoc inthere. Its also hard to get room to push down on the valves to even remove the stemseals when you get there. Fitting them is even worse without the right tool (which I dont think you'll have room for)

A friend made a "sparkplug" fitted with an airhose to hold the piston at TDC, so he could push down on the valves to remove the stem seals with the engine in frame. At the last one, the piston turned over, and the valve dropped into the cylinder. He also spent time to modify some sockets to use to push down on the valves. Much time spent, many frustrations, and still the motor had to be removed.

Unplug a few connectors, remove 10-15ish more bolts, and the engine is out. Motormounts, exhaust, swingarmbolt, and lower shock bolt will just about get you there. I loosened my airbox and pulled it back and removed the motor with carbs still in place in the intake rubbers.

Take this as an opportunity to clean the carbs, grease the swingarm, clean the startermotor from dust, ect, ect, ect.

Keep us updated with how you proceed, and how it works out for you. I hope you do well, however you wish to attack the problem.