According to Jensen567's figures the H2-C still did well at “2A” gear, but pay attention to the already low efficiency at that point (1S input with R075 + R075 sense resistors). Since high mode uses a 60 second stepdown you may try an R100 over the stock R050 (2.25A maximum), but beware of the low efficiency risks, high current losses in switches, springs, etc.
If I were Simon I would go to driver designers and manufacturers and tell them to “stop complaining and make an outstandingly powerful driver, this is for enthusiasts”.
^:)