The ACEA specification may be included for those who have vehicles that were manufactured during the time this spec was in use. Many people do not keep up with oil issues as you do and simply get used to looking for this because it's all they've ever needed.
As far as the company being questionable, I must disagree. I don't have all the information about oils that you do but I have never been mislead by SynLube. I have always received good information from them when I asked for it and believe they operate in good faith.
I still think you should read more of what they discuss on their website and then ask for information from Miro Kefurt. He is a trained chemist and a member of SAE. I believe he can answer your questions.