The answer you're going to get from most people is "lose that IDC crap and use real connectors with crimped pins!"

You can get them from GPE here:
https://www.greatplainselectronics.com/products.asp?cat=80
Plugs for the contacts may be found here:
https://www.greatplainselectronics.com/products.asp?cat=81

You'll need a crimper as well but conveniently GPE sells those too.
It appears from other threads that the 1026-CT aka BCT-1 crimpers are best for your buck.

Definitely go with the trifurcon contacts: 08-52-0125 as they make three points of contacts to the pin. Very solid and reliable connection to last longer.

Unfortunately you did spot one downside of crimped connectors but honestly it's that much of a downside if you take your time. Take a look here to get a good idea of how to tackle looped connections with crimped contacts:
http://www.pinrepair.com/connect/#looped

The article recommends soldering but IMO crimping and soldering don't go together. So note this. Since you'll be "doubling up" wire I would grab some of the bigger gauge contacts in addition to the smaller ones: part 08-52-0072 at GPE as that will nicely fit two wires. That way you have contacts to fit 22-26AWG and 18-20AWG and you can use the 18-20AWG contacts for doubled up wires.

Make sure and buy a good supply of trifurcon contacts so that you can practice making crimps on some similar sized spare wires first before you do those on your game. A little practice and you will have the technique nailed.

When one of my .100 IDC pins went bad on my CFTBL I bought a variety of crimp pins and a couple tools from Big Daddy Enterprises. He was very helpful with suggestions and got back to me quickly when I had a question. It's good to support our friends in the pinball community.

Almost forget to mention to get key plugs if your plugs are keyed:
Part 15-04-0219 at GPE for the plugs I linked above