dongle, ive never made TLC plates so I can't give you any help there, kudos for giving it a go though!
Yes you can also just buy 20cm ones and cut in half etc, another benefit of aluminium over glass! well, you can cut the glass ones with a glass cutter, but only regular scissors required for the aluminium plates.
I was super lucky to have G.O. Joe help me figure out the puzzles pieces, especially as it was such a desperate time for me/my family, I don't want to think about how things would've been different without him. The feedback he gave me in this thread will continue to help people for a long time to come.
One thing I can say though is that your idea might be forgetting that Fast Blue B should be kept refrigerated, and Fast Blue BB kept in the freezer (though im not sure if you meant it as a field test or not). They also degrade very quickly, i'm not sure if it's from light or exposure to air or whatever, but I always freshly make the Fast Blue bath, and try to finish using it within 30 about minutes, because then the fluro yellow starts to turn to a rusty reddy brown, and stops giving good reaction.
See also Beam's Test if you're wanting to test for the presence of CBD, that's a "solution turns color" test, and can be portable/field suitable. Info about Beam's test is also in my TLC tutorial. It doesn't give you anywhere near the amount of info TLC gives you though.
Yes you can also just buy 20cm ones and cut in half etc, another benefit of aluminium over glass! well, you can cut the glass ones with a glass cutter, but only regular scissors required for the aluminium plates.
It takes 20-50 mins for the 10cm plates to develop in my jar, which is about the same size as the plates, usually about 30 mins but it depends on jar/chamber size, temp & humidity, whether you poured 11mL or 12mL etc etc, different solvents might take different times too. I use 12mL because that seems ideal for my jar, from my tests. You may need more or a bit less, but it's not much. Your initial thoughts of "25 mins seems a bit long" is understandable but we're only standing the plate in a very small amount of eluent. If it's getting to 50 minutes though, you might not've put enough eluent in there, and/or the lid might not be screwed on tight enough.
sorry but i'm not a chemist and cannot give advice on any of this. That might sound ironic after all i've said, but i was basically forced to figure out TLC when a family member got cancer but found myself in a position where there was no "DIY TLC for cannabinoids" tutorial available and i didnt wanna buy a commercial kit, so while I now understand the basics of cannabis analysis with TLC, when it comes to mixing chems etc it scares me!
I was super lucky to have G.O. Joe help me figure out the puzzles pieces, especially as it was such a desperate time for me/my family, I don't want to think about how things would've been different without him. The feedback he gave me in this thread will continue to help people for a long time to come.
One thing I can say though is that your idea might be forgetting that Fast Blue B should be kept refrigerated, and Fast Blue BB kept in the freezer (though im not sure if you meant it as a field test or not). They also degrade very quickly, i'm not sure if it's from light or exposure to air or whatever, but I always freshly make the Fast Blue bath, and try to finish using it within 30 about minutes, because then the fluro yellow starts to turn to a rusty reddy brown, and stops giving good reaction.
See also Beam's Test if you're wanting to test for the presence of CBD, that's a "solution turns color" test, and can be portable/field suitable. Info about Beam's test is also in my TLC tutorial. It doesn't give you anywhere near the amount of info TLC gives you though.
And your results WERE vibrant! so your FBB seems good 
