I have been considering doing something similar for a YS-D1, but with the addition of focus light.
Most people find it difficult to get the snoot-light at the right place and it often takes many iterations before the light is right at your focus point.
My idea is to put some of the fibers in front of the strobe’s LED light instead of in front or the flash tube. If there is some continuous light coming out from the fiber snoot, it would be much easier to aim the light. Both the YS-D1 and the z240 have excellent lights for this purpose.
Do you think this is feasible? I don’t have any experience in working with optical fibers like this.