Zabbix proxy: init-command

[SimpleRezo]

Hi

We are using zabbix_proxy docker image.

I'm trying to setup an initial command on mysql connection, for changing wait_timeout and interactive_timeout (because those settings are low (300) on used mysql server):

SET SESSION wait_timeout=86400; SET SESSION interactive_timeout=86400;

Unfortunely I cannot find a way to do it. I tried with /etc/my.cnf.d/zabbix.cnf, but if I set up into [client] section, mysqladmin is complaining about it:

zabbix_proxy    | mysqladmin: unknown variable 'init-command=SET SESSION wait_timeout=86400; SET SESSION interactive_timeout=86400;'
zabbix_proxy    | **** MySQL server is not available. Waiting 5 seconds...
zabbix_proxy    | mysqladmin: unknown variable 'init-command=SET SESSION wait_timeout=86400; SET SESSION interactive_timeout=86400;'
zabbix_proxy    | **** MySQL server is not available. Waiting 5 seconds...
​

First, I don't know if zabbix_proxy is supporting this "init-command" option (I hope so), and if it's the case, how can I setup this.
I'm thinking about client group ("[client-XXX]" section in .cnf file) but I cannot find an option to define it in proxy configuration.

Thanks for your help!