I know it will... I managed to get it to work once, for one image, under testing in my house... Since then, nothing... Thats the really frustrating part about it! haha
I'll get there eventually though. At least I know the pi is able to control the USBrelay board properly now. It's now just a case of getting EKOS to do the same thing and I'll be golden and ready to build my all in one box for everything and add the homemade motorised focuser!
I've been looking around here as I was running into the same kind of issue, then I'm posting my little bit of experience about it in case it could help someone in any way.
Basically I managed once (at first use) to get my D3300 capturing correctly without any extra shutter control device, but then when wanted to use it for real it was not working anymore (shutter not released / "failed to expose" issue).
I've then decided to go for a fresh install before to go for purchasing a kind of device mentioned here, and guess what...it's running properly at the moment (able to get any kind of capture, short and long exposure, FITS and native formats, etc.)