It should be fine for a couple reasons.
1) Wave size is partly a function of tank length, a short tank, cannot make a big wave, in a 40 I think 1" will be the upper limit and you can turn that down if needed by lowering the voltage on the power supply
2) The wave flow is very gentle, it is not a blast but a wash back and forth, even the most delicate of corals fair well in such a flow.