I dont work at Aternos, i am merely a volunteer helper and moderator on two of it's social media platforms.
nevertheless, Aternos didn't code their own forums, as you can clearly see at the bottom in the footer; its made by Woltlab. And still, a no is a no. There is no use to upping the limit because than the next complaint/suggestion comes saying it should be upped more, and this is the best way of preventing spam, and people dont NEED any more than one thread.