I think it is the wrong attitude to say that the Ideas board is the only way one can comment on phpbb.
I see that OP as a genuine effort, not to insult or harm but to give feedback and improve.
I think that some of the comments here try to belittle the OP, like saying he is basing his feedback on Xenforo (Which is one of the leading forum platforms this day) or saying that he is ranting.
For a different example, here on theadminzone -
https://theadminzone.com/threads/xenfor ... nd.145851/ - you see users commenting on Xenforo, "ranting" in a similar way. The developer who is responding don't try to belittle them.
Regarding the Ideas, I have commented on it previously, but they don't seem moderated. I think somekind of a better workflow should be incorporated (add status like: Implemented/being implemented/to be implemented/rejected/on hold/ open for voting etc...)