Modification of progression holes is a very precise job. If you contact ReCarb
https://www.recarb.com.au/ they should be able to help you.
It sounds more like that throttle plates are not installed correctly or the throttle arm itself is bent if there is such a difference between the two at FULL closed position. So long as the body number is the same, the progression holes should be the same, unless they've been modified after the fact.
I would not recommend blocking any progression holes until you know exactly what is going on.
Cheers,
Keels.