How likely is it that if you have 10 spotlight fittings in your kitchen and you fit 8 dimmable Spots and then 2 non dimmable spots that this would stop the dimmable products from working properly?
It seems to be the case in my kitchen that all my lighting fittings must be dimmable or not dimmable for the LED’s for them to work properly.
In answer to your question “How likely”? The answer is quite likely.
Trying to get dimmable LEDs (electrically reactive components) to work with dimmer units designed for incandescent (resistive component) is a job on its own and doesn’t always work due to the design of the dimmer and the design of the LED unit; the electrical power supply designer of the LED may have a totally different concept of what electrical design of dimmer he intends the LED to work with.
Throw another different type of LED into the situation with a different power supply and method of operation and don’t be too surprised that there are issues. Bear in mind that even a lamp from the same manufacturer may cause issues due to different circuit design changes/different designer between the units.
Bear in mind that as well as a danger of dimmable LEDs (or CFLs) damaging the dimmer or themselves there is a strong possibility that the system will not work as the user imagines it will, complicated even further by the fact that the system may well work with 8 lamps but fail to function with 9.