KYB for Proprietary Firms in Europe/UK - Anyone Encountered Hassles?

I'm currently considering Prop Firms that focus on FX and Indices, specifically those with low spreads and reasonable leverage. I've looked at several, most of which are registered in Europe or the UK. The issue I'm facing is that the KYB process is extremely detailed. Some firms ask for redundant documents, and the process is very slow, even more so than opening a bank account. I'm not sure if others who have experience with these Prop Firms have encountered similar problems, or if there are any firms with a smoother process. Please share your experiences.