They won't improve Engine efficiency one little bit,
but those Ignitions do "wear-out" Spark-Plug-Gaps at an alarming rate,
as they are designed to deliver an extremely "High-Current" Spark.
The Spark-Plugs are replaced for every single quarter-mile run, as well as many other critical parts.

Nitro-Methane-Fuel requires a serious flamethrower of an Ignition-System,
this is mostly because the Air/Fuel-Ratio may approach as rich as ~3 to 1,
so there is always a huge amount of liquid-Fuel in the Combustion-Chamber.
Sometimes the Engines actually "Hydro-Lock" on excessive Fuel.

They use custom-made, Aircraft-style, Magnetos,
yes 2 of them, with 2-Spark-Plugs per Cylinder,
this is because Nitro-Methane burns very slowly, ( compared to Gasoline ).
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Another note on chamber design and compression

With direct injection you don't have to worry about pre ignition issues as severely as with port injection or like my carbed 300 6

My 300 is running fairly high dynamic compression around 11.25:1 but I have a fully ported and mirror finished head which makes a huge difference too with 39 degrees total timing by 3400

I also run a reverse cooling system so the 185F coolant hits the head first

Used to be with such a massive head that cylinder 6 would get up to 198F and cylinder 1 around 210 since it was the last cylinder to be cooled



Also I'll be drawing out my diagram for how I'm gonna time the injection and have some good ideas for fuel correction pulse width and dwell