:I used metal cutting blades (18 tpi?) To avoid splintering on the edge, I cut perhaps 1/8" to 1/4" out side the line, then trimmed down to the line with the low-angle block plane that I used to make the scarph joints. The trimming goes very quickly.

Perhaps try a metal cutting blade on scrap 1st, to see if splintering will be a problem....this only happens to me when I'm using fir plywood.

Good Luck!