Crashing exploits in Minecraft bedrock

I have reported this before, but there are lots of spammers, they maliciously crash and lag Minecraft bedrock servers. It works cause they use small font/text, and it overrides mc. This has happened to my server before, it just did 10 minutes ago and that is why I'm reporting it again. I'm hoping in the newer mc versions, this can be fixed like adding a limit on how many texts or fix lag. I really hope! Thank you, - from a passionate mcpe map maker.