If you knew me better, while reflecting on my previous comment about having used 409 to clean Mac plastics since 1984, you would know that "it does NOT damage plastics." :b&w:
I treat my Macs like they are a part of my own body almost. So no, if I detected even the slightest discoloration, cracking or other "damage" I would have ceased use of 409 and never recommended it here. But the simple fact is, it has worked for me for years, and yes, that includes repeated uses on the same plastics over and over during a span of many years.
If anything is going to damage your plastics (i.e., "blooming") it is the use of H202 in very high concentrations, which is why my approach to RetroBright followed LumpyDog's work, using low strength 3% drug store H202. So use the 409 a few times first. And if you want even better results (i.e., deyellowing), go with LumpyBright.