Most modern automobile engines have piston sprayers now. It is not uncommon to see 300,000 miles on them with little to no percievable cylinder wall wear. The weakest link on the air cooled engine is the cylinder walls. Why wouldn't someone want to try sprayers on something besides Flatheads? I never saw an example of long stroke cylinder / piston wear but it only makes sence that sprayers wouldn't help.
Someone with a ruined right side case needs to chime in here. Is there enough room to squeeze them in like the Flatheads? Is there enough oil supply already up there in the tappet blocks? Would the tappet block oil supply passage need to be opened up? Is there an oil pump available with enough volume to do the job? Would all this be worth the trouble?