Sublingual advantages/applications

Greetings.  Information has proven difficult to obtain.  Any help greatly appreciated!

Specifically my questions revolve around absorption, lipid carriers, and adjusting dosage down.

My understanding is that sublingually held ...increases absorption directly into blood.. bi passing digestive process and is therefore exponentially more available.  Potent.

However it seems that combining w a bit of olive oil is better?  Right now i am am just thinking fisiten as an example (to keep things simple) but imagine this could apply to everything from b complex to metformin to nattokinase.   But maybe some substances dont need the lipid. So obviously a huge topic.!

Any feedback or links?  

For the record- i haven't noticed any appreciable differences... but experiment off and on anyway.  :)  w fingers crossed.  Thanks so much.