As great as UE4 is, I continually find its lacking in matrix math (beyond the RECTOR built-ins). In my own game dev, I'm constantly adding functions into a BP file to bridge the gap. If you run across any common operations not covered by UE4 in blueprints, post them here and I'll add them. I'm also working on building up stats and transcendental function packages (working on stats phd so it's my bread and butter). Recommendations are being taken for these as well. Of course, if anybody wants these files I'm happy to share. Math is free, and has saved me countless times overcoming whatever engine bugs I run into.