How M-class variants might have been used in the Second World War

How might four each of the M1, M2, and M3 designs have been used in the Second World War?

The minelaying M3 type has the clearest role; submarine cruisers are much harder to place confidently in a practical wartime employment scheme.

The performance of submarine cruisers remains uncertain, while minelaying offers a clearer practical use. This alternate construction programme produces four purpose-built M3s and eight vessels converted to the M3 role instead of preserving a large force of every experimental variant. That choice concentrates construction on the design with the clearest operational task. The South China Sea is one plausible area where these minelaying submarines might have been employed.