I do this on my Xtool M1 with both the blade and laser cutter, both seem to work fantastic though the laser cutter leaves a little burnt residue.
Super easy to come up with the trace, just throw your part on a flatbed scanner, scan and trace it out in FreeCAD and send the SVG out for it to cut.
BBK actually doesn't make a 61mm gasket (I believe for 3502 part number), it still has 58mm holes so you're really better off just going custom when it's $20 for the wrong gasket lol that you have to hack up anyways.
I love the reduced time to get things with this approach. I just keep enough of different types of FelPro gasket paper on hand and have them cut as needed, way faster than Amazon!
My friend has been running a Nylon IAC spacer ln his turbo 351W foxbody with two laser cut gaskets to go with it for over a year with hard racing in high temps and all of it has held up great.
Photographing fairly flat angle with your phone and then scaling the imported image using a dimension such as the diameter of a screw hole or something will get you VERY close as well for more prohibitive items!
3D Scanner is really worth while if you do a lot but that's a bit of a barrier to entry for most people currently but hopefully follows the trend of printers getting better and more affordable.