Has anyone ever used colder plugs with 87 octane gas

[jsap]

I know that Mercedes is adamant that years '86+ need premium gas. But, of all the possible mods you could do to an engine, including various injections, water inductions, boring, port matching, ceramic glazing, etc..., and thereby possibly needing a different octane rating and spark plug heat range than originally specified by Mercedes engineers, do you suppose that this simple mod would be feasible:

Use 87 octane gas, with colder spark plugs? If that's not enough to eliminate pre-ignition, use a 70* thermostat?

Since lower octane is more prone to pre-ignition, my thought would be that using colder plugs would reduce than risk?

Also, my assumption is that my M119.982 is a 10:1 ratio (is this right?), which is not that high anyway.