Most Luthier's sites will open with a statement of their awareness of, and adherence to, the traditions of their exacting, centuries old trade. While I am well versed in the traditions expected, and have been building stringed instruments for more than four decades, I have practiced several other professions at various points in my life, from sculptor, and historic restoration carpenter to mechanic and machinist, and have accrued skills and frames of reference that are not common to the fiddle trade.
I have experimented widely to suit my own imagination. I have tried unorthodox materials, reintroduced forgotten patterns and drawn new ones to suit specific client's requirements. I have solved a few structural problems that have plagued bowed string instruments from the time of their first appearance, and some that have become problems in the age of high tuning pitches and high tension stringing. An issue of particular interest to me is playability, and the development of forms, sizes, and set ups that are as Ergonomically aware as I am able to make them.
A musical instrument is a prosthetic device that allows you to make sounds that your body alone cannot make. In so far as possible, it should be made to fit you and the music you intend to play on it. If the tradition is in the way, and a practical option exists, the prudent player would be wise to consider the alternatives available. Smaller players can profit from the use of 5/8th basses or 7/8th cellos if the standard body sizes and string lengths cause them difficulties or damage. The one in a thousand talent as a child should have size appropriate instruments available to them that are crafted to be truly responsive and sonorous rather than having to play on the standardly available factory goods built for durability as their primary virtue. Nearly any chinrests can be custom altered to better fit a given face by passing it back and forth for a few hours until it conforms to your specific jaw and preferred head angle,(That's one of the things rifflers and scrapers are for.) Chinrests can be custom made out of materials like olive or apple that are less acidic and micro abrasive than ebony. Necks can be either wider or narrower than standard, String lengths can be cheated shorter, or finger boards can be made with extended length under the high strings. A player of second violin can benefit from using one of the earlier, larger patterns of fiddle, because it provides a darker, different tambor from the more modern violins, making the second voice more easily distinguished from the first. If a violist has damaged their shoulders, hands or neck to the point where they can no longer play da Brachio, the instrument can be fit for an endpin, and they can learn to play down, rather than abandon something that they loved enough to spend years in acquiring musical skill. Instruments with extra strings, patterns with cutaway access to upper positions, the invention of instruments that have yet to be made, are all possibilities. When "The Tradition" fails to meet your needs, you should request that some imagination be exercised on your behalf, though you first must engage your own.