Validate change when there's no value

I know, the topic cannot be more confusing :slight_smile:
I’ll try to explain:
I’m building a custom form to update client details. Each value in the client table has it’s own input field in this form. I’m fetching the current values with a Lookup column for each such value, so we have the “new value” columns and the “current value” columns.
There are many validations going on (=the point of the form, compared to native “Edit” form). One of these validations is to check if “new value” equals the “current value” of the respective client column. If they are, I’d like to flag it which will than cascade to not allowing the form to be saved (until corrected). As I don’t really care which such new value is equal to its respective current value, I’m fine with checking them all in one long ITE column. As you can see below, my goal is to always reach “NA”. The “then” values are not very relevant actually and they’re just there to show the ITE stopped somewhere before reaching the bottom else (=“NA”).

Now, the challenge comes when comparing two empty values (=both new and current are empty). Such an occurrence shouldn’t be flagged. It means a specific detail regarding the client has been missing before entering the update form and it’ll remaining missing after submitting this form. These details are carefully monitored in other forms in regards to making sure that indeed each client has 100% of the mandatory information, allowing the non-mandatory to remain empty.
Assuming I haven’t confused you completely, I’d be happy to hear your thoughts on tackling this.

Here’s one idea. What do you think?

If you are using a custom form then maybe you could add a custom action to your button…

If new name is empty AND lookup current name is empty then show notification “Enter Name” → else submit