You are trying to over simplify an incredibly complex variable set.
You've been a member here a long time, and in that time, there have been many nuggets that contribute to our collective knowledge of how our motors work and the effects and tradeoffs of various actions.
There is no free lunch.
A number of the mods made here improve power at the expense of more fuel used. A few mods made here use the fuel more efficiently, thus gaining both power and range. All of these are far more expensive than purchasing TuneECU and the Lonelec cable and loading a de-restricted map.
Higher efficiency can *only* come from a change in the thermodynamic flow, and this necessarily involves more stress. Whether the added stress becomes a factor in the number of miles you are likely to ride, depends.
You stated you don't want to change anything except the mapping to de-restrict. This is only meaningful in the context of the Roadster / Touring differential, and so the link to the map I offered, does that.
This is easily installed, and in the process, you save off your stock map. Say you run through two tank fulls of fuel with the new map, and don't like it. Easy peazy hook up TuneECU and reverse it.
Anything else is going to cost - more.