I have had it recommended to me to switch to pre-mix when I do my porting and shave the head. Is this the same feeling shared by must people?

 

Since you're going to add a lot of mods to the TB, and the jetting will be much richer than stock. The oil injection will have the same output amount and the amount of fuel passing through the engine will be much greater. This will throw the fuel / oil ratio off considerably.
Add some oil to the fuel and let the engine live longer.

 

There have been many failures due to the oil injection setup. pre-mix does nothing more than assure you that you are getting the proper ful-oil ratio. The higher modified you machine is, the more i would lean to pre mix.