@lemonhaze I've worked 40+ years in an industry where all equipment is continuously in service with very short outage times. So there isn't much testing time available. Generally the engineers (I'm the engineering manager) do a lot of research and have one chance to get it right. It needs to be well designed, prefabricated, and ready to instll quickly. Which is my plan here. I plan to have my speakers down for 1 day, at most 2.
So I guess it is natural that I took that approach with this project. And a good thing too since I've been very slow to get the internal crossovers made. Got traction again when I decided to go external and think I'll have them done in a couple of weeks. Picked up the wood for the caninet this morning after my hike. Right now I'm waiting for my sawblade to come back from the sharpener. Also the Neutrix connectors for the cable from the crossover to the speaker were backordered but I found them somewhere else. It's al coming together.
So I don't plan to try it with and without the bypass capacitors. I chose the .1uF Dueland Copper-Sn foil based on experience and recommendations from friends. If I was doing it now I might go with the copper silver for $30 more each. I agree with Erik that .1uF is the right size.
If you are anticipating doing this job yourself feel free to send me a PM. As a DIYer I'm always willing to spend time helping others.
Jerry