I despise headset routing because it's just plain stupid, but I tolerate internal routing for shifters and droppers since I don't replace my housing too often.
Just leave fucking external cable clips for the rear brake hose! It's much easier to get a perfect rear bleed when the brake line is 100% vertical and you can tap it all the way up with the caliper on the ground. I use an old handlebar that I bolt the lever to with a quick grip holding the bar to something higher and just make the bubbles go up. It's easier to clean the floor than the bike, and then I can just bolt it to the bike knowing I won't have to fuck with it again. With internal routing, since I'm cutting the lines, I'm always going to bleed it again when it's on the bike to make sure no air entered, which I would't have to do with external routing.
Just leave fucking external cable clips for the rear brake hose! It's much easier to get a perfect rear bleed when the brake line is 100% vertical and you can tap it all the way up with the caliper on the ground. I use an old handlebar that I bolt the lever to with a quick grip holding the bar to something higher and just make the bubbles go up. It's easier to clean the floor than the bike, and then I can just bolt it to the bike knowing I won't have to fuck with it again. With internal routing, since I'm cutting the lines, I'm always going to bleed it again when it's on the bike to make sure no air entered, which I would't have to do with external routing.