Wow lots I can say about this one!
SCR vs MOSFET for most home products comes down to what several are saying here. Leading vs Trailing Edge aka forward vs reverse phase control dimming is a big distinction. With SCR, leading edge dimming is the only option. With MOSFETs (and the right firmware) both are possible. The key difference is that a trailing edge dimmer will — in most cases — dim loads that are not purely resistive quite nicely. A few other components are necessary such as transient voltage suppressors and a snubber will help balance the effects of the inductance.
In short, without getting too deep into the details, if you can stick with MOSFETs there are many more options available to you for the future of the product. Having a leading and trailing edge dimmer in our walls would be an amazing advantage to properly dimming the ever increasing variety of bulbs on the market. I’m also a bit puzzled by your CM’s struggle to secure parts. There literally are zillions of MOSFETs. Many have comparable specs. Another alternative would be to use IGBT devices (insulated gate bi-polar transistors). If you are considering “switching” (…someone see the pun please…) to an SCR design there’s already some scope there. It could be better to direct that effort towards re-specifying alternative MOSFETs or some redesign with IGBTs instead.
This is not a put down of SCRs in the least. You would be able to get solid and reliable performance from an SCR design and I suspect your BOM cost might drop a little too! But in the long run? With difficult to dim LED bulbs everywhere? I’d go MOSFET if I could.