Timing Light W/Advance

The advice came from a Summit racing catalog tech who put me on hold for 5 minutes talked to his supervisor who called a msd tech. Thats what he told me. If it was true why wouldn't it say so it the install instructions? Just confused. If so mant people are useing the advance light with msd without any problems, I don't think I'll worry about it too much.
Thank you all for your input. :salut: