I picked the LCDi4 up early 2020 after reading up this entire thread. Given fit was recently brought back up I thought I'd share the solution I came up with which has been working perfectly for me on the fit (comfortable to wear 8hrs a day and can shake my head and they will not come out of my ears!). Although, it is highly dependent on one's ear anatomy and how far in one's ear one wants these.
I used Radians Custom Molded Earplugs to make myself a set of custom ear fins. Before starting the process of making the molds I decided if I wanted to use ear tips or not to achieve the positioning I wanted in my ear canal (for me I choose to forgo ear tips). I then found where, without tips, wings, or hooks I wanted them to be positioned. I took a mental note of what that looked like from the outside as I would have to replicate this position later when making the mold. I then taped the tip of the LCDi4 and followed the instructions to make the ear plugs. Once I had finished putting the molding mix in my ears I push the uncabled and taped LCDi4 into the still fresh mold in my ears and let them set.
It's a bit tricky to get the right position in one go so I made a second set and got it as good as I could make them (see pics attached).
Having a proof of concept in hand I set out to contact ADV sound (who make custom ear tips) and Audeze to see if I could get some custom ear fins made. ADV was not willing to position the IEM as deep as needed to provide a more secure fit than the ear hooks. Audeze consulted internally for sometime if they would be able to provide such a service even at a higher cost. Ultimately they said no given they had manufacturing concerns for the thin areas of my molds. However, the molds I made are plenty good and I have used them for almost a year now with not problems.