Hi,
When you have this many rules, you should use the “No reversing of this rule” for any rules you don’n want to “reverse” if they do not match. Use the “Stop if this rule = true” and maybe the “and jump to” to skip rules that does not have to be validated.
If you don’t use these options, all 77 rules will be evaluated when you load the form.
Also you should put vLookups in separate tabs to prevent them from loading when the form loads. If you do this, the vLookup will only be loaded if you click the tab containing the vLookup.
Hope this helps,
Alexander