The answer to this is essentially no. In theory, it can be done but is absolutely pointless for many reasons.
It is not necessary to have a higher powered steam generator on the back of your shower cabin. The added expense would be prohibitive, especially when weighing up the advantages and disadvantages. The size firstly would cause issues as the heavy duty generators are far bigger than the ones for the showers. Also the power connections for your shower control panel run through your generator, so the control panel would require changing as well. Other items such as the speakers and lights will also have different connections so you are causing problems and a headache for yourself.