If I am reading the regs correctly in CFR 60.129, a distinction is placed on the class of aircraft as it pertains to single or multi engine. So, you'd have to do a separate checkride for Commercial Rating in each. There does not seem to be a distinction between ASEL and ASES. Is that correct? There is mention in CFR 61.129 paragraph 3, Section ii that mentions 10 hours of training in a seaplane for applicant seeking a single engine seaplane rating. There is nothing else in the section that mentions seaplanes at all.
Is a separate checkride and "rating" required for Commercial ASES? Or is it just considered Commercial Single Engine regardless? If you have trained and passed checkrides in ASEL and ASES prior to commercial rating, are you okay to do commercial flights in both?