Today I came across something I missed as a type field in the ACF which is a text area style ACE Code Editor (http://ace.c9.io/)
Is there any possibility of the ACF staff working on something like that?
Hmm… Have a look at this plugin: https://wordpress.org/plugins/advanced-custom-fields-code-area-field/. I think it might help.
I’ll pitch it to the developer and see what he thinks.