didn't talk to them (tried but no answer) but larger elements is the basic mod.
Different levels then can only be different adjustments.
Basically here is the full load adjustment (together with other adjustments that are necessary). Full load adjustment is moving end of injection. With the (not matching the cam profile) wrong 7mm elements the end of injection is too late even with moderate full load adjustment all beyond that makes smoke rather than power out of the added fuel and stresses the cam/roller surface.
The best to adjust the governor is to remain in the range it is designed for, using its full operation range.
If you don't want to spend this money just get the 7mm elements and get them installed somewhere in the US and you are at 90% of a "Myna" pump. Not talking about added ALDA etc. on a 5 cyl. M...

Tom