Hi there,
Backend's implementation for ad_form is within packages/acs-templating/tcl/form-procs.tcl. Plus, frontend templates can be found within packages/acs-templating/resources/forms/
The issue was related to how submit button has been named.
If the switch -has_submit is in place, then to re-use acs-templating resources, the submit button must have its name assigned as "ok", such as:
...
{ok:text(submit) {label {[_ evex-item.Save]} {value 1}}}
Otherwise, the code available in acs-templating pkg won't be aware of it, then customized chunks of TCL and Javascript get in the scenario.
Best wishes,
