Fo me, this brings up the question: what is a custom cuemaker? If you can't order the cue with your specs, is the cuemaker a custom cue maker? There seems to be a spectrum of custom cue makers: for some cue makers you can order any spec and any wood and any design. For other cuemakers, your choices are more limited. For instance, I read an article about Haley cues, and it said each of his cues is unique, i.e. you can't see a Haley cue you like and order it. For some reason, I don't consider a cue maker who won't make a cue with your specs to be as talented as a cue maker that will. In my narrow uneducated opinion, a good custom cue maker needs to have the tooling and knowledge to make cues with a wide variety of specifications, e.g. different lengths, varying butt sizes, requested balance, stiff v. soft hit, etc. And, they have to have the artistic talent to make cues that appeal to you and have good craftsmanship, e.g. sharp and even points, windows with mitered corners that line up perfectly, etc. If I'm not mistaken, there aren't many fully custom cue makers: most have a certain hit they build for, and some only build to certain specs.
I emailed one expensive, well regarded custom cuemaker, and I asked them if they were taking orders, and if they were, I asked for an estimate of cost and completion date. I sent them several pictures of the cue I wanted made. A couple of years ago, a seller on facebook listed the cue for sale, and I contacted the seller about buying it. Unfortunately, it had two issues for me: no bumper and the butt was too thin. So, I asked if I could have that cue made with the addition of a bumper and the butt having a diameter of 1.29-1.30 inches...and the cuemaker went ballistic (my interpretation):
Geeze, I sent them several very sharp photographs of the cue I wanted made, but they needed a written description just because I asked for a 1.29" butt? Of course, the cuemaker knew photographs were better than a description, but I guess because I dared to ask for my spec on the butt, they were unwilling to build the cue for me, so they put up some impossible to jump through hoops for me to negotiate.