I bought a two pack of jigsaw blades for metal cutting but with a reciprocating saw shank. Easier to get the nose of a reciprocating saw into places a jigsaw will not fit. If you hack it up too bad you can add a reducing washer to cover the mess. Also easier with the little one hand reciprocating saws which have 1/2 the stroke length of the full size tools. Plus they have led lights to see what you are doing.
Bill D.
https://www.ridgid.com/us/en/one-handed-recip-saw