A side effect of the ocarina's widespread use as a musical toy is that their development has been relatively stagnant for some time. As far as I'm aware nobody has thoroughly examined them under the light of modern research techniques and computer simulation. As people become aware of the ocarina as a serious instrument this will start to happen and its pot luck what will result. The problem is that any new discoveries would be patentable. Should such a discovery be a 'game changer', something that everyone wants, this could seriously disrupt the ocarina community. I don't think this would be a positive thing.
Despite what the name implies, 'the ocarina' is not a single instrument; the term refers to a haphazard collection of loosely related things ranging from whistles that only produce a single note, to art pieces, serious performance instruments and everything in-between. Even among serious instruments there are *many* variations in timbre, breath response and ergonomics:
Timbre: The ocarina's physics are capable of creating a wide range of timbres, from the characteristic 'pure' sound, a pure but airy sound to a reedy timbre like exhibited by Gosselink and Pacchioni ocarinas. What is optimal depends on player taste and the genre of music.
Ergonomics: Ocarinas vary hugely in their physical shape and hole placement. Everyone's hands are different and no single design can cater to all. People with a physical disability should not be discounted either.
Tuning: As an ocarina's pitch depends mostly on hole size instead of position, it is trivial to tune them to non-major scales. Tunings making use of microtones are also possible. Another consideration is that ocarinas are temperature sensitive and must be tuned for the temperature range they will be played in.
Pressure response: An ocarina's breath curve is determined largely by the maker and can be much more free-form than other wind instruments. They can have very low pressure, very high pressure, a regular change between there high and low notes or increase exponentially for a louder high end.
Volume: Ocarinas can be made to produce a wide range of volumes, from relatively quiet to ear splitting. What is preferable is completely situational.
Visuals: While these goals are often at odds with each other, ocarinas can be both good instruments and sculptures to some extent. Such designs are almost always one-off commissions.
I believe that the open, communal development we have today is critical to fulfilling the needs of players. Music is inherently a subjective art and so are the tools used to create it. One maker cannot cater to all of these variations as the number of permutations is enormous. Makers produce either designs that they personally like or what sells the most. Plus, the creator of a design is rarely aware of all applications. My Pacchioni system double in D for example: this design works well for Irish traditional music but Pacchioni was not aware of the use case. He isn't interested in the genre.
This is especially problematic with ocarinas as there playing characteristics are set by the maker and cannot be changed. It is fine when development is fully open but if things start to become patent-encumbered, it may become impossible for a player to obtain what they want. This would create considerable fragmentation in the community and bury certain designs just because they are not as popular.
Simultaneous discovery also needs to be considered. Everyone works in the same universe constrained by physics. When someone has a problem they experiment with these rules and may find a solution. However the number of solutions are finite, two or more people looking at the same problem can easily arrive at the same solution. I highly recommend reading "what technology wants", which covers this in detail.
When I began making ocarinas, I was terrified of other makers as I feared that their mere existence would ruin any chance of making sales. However, this no longer bothers me as I can see that the ocarina is much more diverse than I realized. Makers can still compete on quality and by providing playing characteristics that appeal to a different audience.
Following the 80/20 rule, 80 percent of people will be happy with a single design. Small makers fill in the 20 percent: high end, niche or one-off items. I don't believe that they compete directly with larger makers and blocking them would reduce diversity. So what would I suggest? Simply don't tell people what you are doing. From a naive point of view it is very difficult to figure out why a particular design works. Ocarinas are insanely finicky and changes on the order of 0.1 mm can make a huge difference.
While I am aware that cloning, 'knock offs', and counterfeits are a thing and dilutes a brand, I think trademarks and copyright are a better solution. It blocks lazy copying while allowing people to take inspiration. If you must patent something at least make it licensable for a sane cost. Small makers usually have small margins; it doesn't take much to make the business uneconomical.
Making an idea popular requires either an enormous marketing budget or an open design. If something is free to implement, its public visibility increases naturally as there are multiple sources, thus multiple marketing efforts. Increased visibility increases the number of buyers, which increases the possibility of making sales. If the design is named after the maker, this also raises awareness of their existence, such as my mention of Pacchioni above.
So in summary, I strongly believe that a diverse community and market is better for everyone.