Separating free from free for commercial use is the useful part here, and quoting each vendor's own page rather than a summary site is the right standard. I'd add one more column to the table: what happens to videos you've already published if the terms change or you downgrade. Some services tie commercial rights to the plan you held when the audio was generated, others to the plan you're on now, and that difference matters for a channel with a back catalogue. Keeping the generated audio plus a dated copy of the terms page in the project folder is a cheap habit that settles the question later. Being upfront that ForgePlug only has English voices for now helps the comparison too.