I've seen this question posed to the forum several times over the years and don't think much of it...seems very expensive and gains nothing.
Seems like alot of work when I regular AWS D1.1 full pen splice should work...provided the beam was sized correctly for the application to start with. You can't develope anymore strength than what the beam will carry to start with anyway and a properly executed full pen splice is supposed to develope that much. By zig-zagging the cut...you just added more work to properly bevel and weld it together. A straight cut would be better/more cost effective in my opinion.
B-U4b for the flanges and web.