Got it!

Earlier today, I was thinking about my difficulty and what was causing it. Initially, I thought I had to use the regular settings.mdb in the conversion package. Then I went, 'wait a minute, why don't I try the ET3-S in the package?'. So I tried it out and BAM! it worked out. The instructions at the beginning didn't include a specific phrase like "if you have an ET3s ESC, this is the file you need to copy/paste into the castle creations directory."

So now I have a 4s powered drag car. Fun times shall be had now.