Firstly .Ive enjoyed reading through this thread ,and have gained more insight into the 'Pros' and 'Cons' of various common methods of modifying by doing so.
Id'e like to ad something that I discovered by accident,and that I haven't seen mentioned anywhere .
The con rod in the JS vox 21 and Innova engines when fitted reversed ,ie,oil hole towards back plate,transforms the engine completely ! For the better!

The engine becomes easier to tune,longer run time,more linear power band ,and a screaming top end,with a little less bottom hit ,and gets longer life.

The rod is offset to one side at the piston end ,and in the original orientation sits closer to one side of the piston (exhaust side) ,and wear can be seen where it rubs against the piston pin journal inside.the rod also contacts the backing plate and wears rapidly,ie ,tries to walk off the crank pin.One side of the rod journal is milled curved and the other flat and larger(like many other rods) but in the JS they put the flat side facing the crank and the dome towards the back cover ! At top of stroke the rod is almost clear of the back plate where its milled to clear the piston skirt , and because of the smaller curved side of the rod is facing back ,it catches.
We just drill a 1.1 mm hole from the curved side to intersect the original oil hole and its done.(I / WE think the factory might of made a mistake and drilled the oil hole the wrong way around ) Ive done this mod to many of the early and late JS's and so have others over here (many from new) and every one loves them .