Rework of 4000 sheet metal parts-adding a larger hole

[Brad93]

Laser but you will need a jig that located on the existing features to allow fast indexing of the part

 

[E T]

Plasmacutting them by hand with a jig will give you lots of cleanup work on all the parts.
Even a small plasma will zip through 1.5mm, but at 4000 pieces your travelspeed is going to be all over the place resulting in dross or uncomplete cuts.
And you'll need good fume extraction and ppe. Especially if they're galvanised.

 

[bricol]

P.s. looks like the plate has been galvanised was that done post forming and does the non galvanised edge after reprocessing need to be taken into account?

Looks like zintec to me. Bare edges will stay remarkably rust free due to the galvanic effect of the coating - I have had guillotined and folded bits (actually used as bookcase dividers in our old cataloguing system) standing outside for the last 20 years (as the last place closed 20yrs ago) and they are rust free.