The words custom and production, in regards to cue makers, are absolutely meaningless. There literally are no such things.
One reason why is that everybody has a different definition for "custom" and "production" cue maker. When everybody means something different, those terms have no real meaning.
Then there is the fact that for every definition of "custom" cue maker there is, including all the ones in this thread, there are examples of cue makers who are widely considered by the person using the term or the market to be "custom" makers who do not meet that definition, and/or examples of cue makers who are widely considered by the person using the term or the market to be "production" makers who do meet the definition. And for every definition of "production" cue maker there is, including all the ones in this thread, there are examples of cue makers who are widely considered by the person using the term or the market to be "production" makers who do not meet that definition, and/or examples of cue makers who are widely considered by the person using the term or the market to be "custom" makers who do meet the definition. If you think you disagree with that, then let's hear your exact definitions of "custom" and "production" cue makers where this isn't true, but nobody has ever been able to do it yet. And if you can't do it, you have to admit that the terms are more or less meaningless and have little value.
The closest thing there is to a consensus in their definitions is that the prestige of the maker is a large part of most people's definitions, with makers they perceive to have more prestige in the marketplace being labeled "custom" makers, and those they perceive to have less prestige in the marketplace being labeled "production" makers. Regardless of how common it is, it is still a pretty dumb way to define the terms in whole or in part, yet perceived prestige is the thing that carries the most weight in most people's definitions.
Before somebody calls me on it, I too use the terms on occasion for ease of conversation in the same way that most use it, to either denote the cue maker's prestige in the market, or to denote what they are almost universally labeled as by the market (whether right or wrong). It's still dumb though, and I try to avoid the terms for the most part.