I have done this on an Alfa Romeo ('66 Sprint GT), but not on my e9. It is a great idea, and aftermarket fuseblocks are available - like the ones from
http://www.wiringproducts.com/contents/en-us/d136.html?gclid=CMDq_tnLpaQCFUNe7AodYTe75w pictured here:
When I converted my Alfa, I was doing a total re-wire that included relocating the fuses from underhood to underdash, and fabricating a whole new harness. The Alfa wiring is much simpler than that on an e9 - there is no A/C, and fewer electrical components. My point here is that working in the confined underdash area of an e9, and extending/re-terminating all of the wires that attach to the fuseblock will be a challenging job. But the blade-style fuses sure are a big improvement over the old-fashioned pointy ones.
Here is an "in-process" shot of my Alfa's wiring and fusebox (it looks a lot neater now that the job is completed). As you can see, I did this before installing the dash, providing much more space to work in. The Alfa only needed 6 fuses; I used a "3x2" fuse configuration because it was narrower than the "6x1". The challenge with doing this on an e9, is that you need 10 fuses, and I don't think an aftermarket blade-style 10 fuseblock is available. Maybe two "6x1".