Isolator’s (ISO7720) recommended current
The electrical and switching characteristics are guaranteed only as long as you stay inside the recommended operating conditions.

When you draw a higher output current, the voltage drop will be higher. Figure 11 shows only typical values; you do not know how large the actual voltage drop might be.

Power dissipation (&lt; 2 mW, assuming a 0.3 V drop) appears to be safe, and the higher load should not affect the speed at which the output transister themselves are able to switch. So as long as your load works with the reduced voltage, it should be fine.