I sense your frustration but hang in there buddy! The thing is changing lamps is not only a hassle it means you are deciding when the plant is ready to absorb different spectrums and intensities that is determined by your flip photoperiod. This represents a period of stress for the plants and if they are going to hermie or fall prey to disease or infestation it's going to be when their defenses are down. That is the reason I've always been a proponent of giving the plants a broad stable spectrum through out the entire growth cycle and as in nature simply let the photoperiod be the trigger to flower.
As to adding MH to the Inda-Gro that wouldn't be necessary for a few reasons. MH lamps are spectrally unstable and shift dramatically upward in their first (burn in) 200 hours of operation. They will stabilze for the next 2000 hours than shift to lower kelvin values for the remainder of their lives. There is ample UV-B spectra being emitted and vegetative growth with tight internodal spacing is as good as you're going to get.
I've never grown with an iGrow product but my understanding is they have different lamps for veg and bloom. It's hard to say what spectra any of their lamps emit because they refuse to publish spectral distribution graphs as they consider this proprietary information. However a two lamp approach is not the direction I would take for the reasons previously stated. If your doing good with them that's great that you've dialed it in for your crops. But for the added cost and hassle of replacing lamps I would be willing to bet that even without the Pontoon, which Inda-Gro offers for the additional 660nm at lights on and 730nm at lights out, the finished quality is going to be better and weights would be at least equal to an iGrow finish.
Since you own both brands you should consider doing a side by side in which you don't move veg plants that started under the Inda-Gro to HPS. Let the plants finish under the Inda-Gro and see the difference. If you want to be fair to the iGrow don't run the Inda-Gro side with the Pontoon and keep the flowering photoperiods the same at 12/12. Everything being equal the finishes will favor one over the other. When you add the Pontoon in and push a 13/11 flowering photoperiod there won't be any doubt in your mind as to which approach works better for consistent quality and crop after crop returns. The results will speak for themselves.
I would have to agree that these are not inexpensive systems to purchase but I can tell you that the cost of my lights has always been recovered in less than one crop and in some cases a 1/2 crop cycle. What is particularly satisfying is that I've got gardens running on the same lamps now for going on four years. Which means the original price to purchase these lights is a distant memory.
I'm getting better results with the Igrow induction lights anyway. A third less yield though, but better end product.
A third less yield is completely unacceptable. And for what? A reduction in heat? More natural to be around? While one could argue that 'you get what you pay for' I would say that is not at all the case at all when comparing an iGrow to an Inda-Gro product. iGrow will be more expensive to purchase and when compared to the Inda-Gro trichome, resin, oil and terpene production is superior to HPS finishes which unlike the iGrow will not require you to to give up 1/3 the weight for those results.