Some methods offer to receive a huge amount of text. Most of the time, this text is JSON/XML data.

The database limit is 64 KB but the limit of the collector/receiver item is much more - unknown limit.

Kindly document the limit, for example in zabbix_sender section when it allows to send big data:

i, -input-file input-file

https://www.zabbix.com/documentation/5.0/en/manpages/zabbix_sender?hl=zabbix_sender