That seems quite insane as it has to load engine each time form is opened.
As far as I can tell by watching, if no URL is specified for the web viewer, nothing is loaded. But a button in the background can work also.
Your save script can do it's own check for data entry errors before committing the record and thus you can avoid the validation error interrupting your script with a validation error message.
An alternative approach is to set up a layout with global fields for data entry. Your save button then either creates a new record and copies the data from the global to corresponding non-global fields in the new record or if does the same type of data transfer to update fields of an existing record.