Among the treasure trove of nonsensical advice on user forums is that of measuring float bowl fuel height using a piece of clear hose attached to the float bowl. Now, don't react. I call it nonsensical because it, like many things on forums, is something that originated in a way many are ignorant of yet seem compelled to use when they don't even know its true context. Like putting thread locker on fork damper bolts, or oil in cylinders during a compression test, that sort of thing. 1 These all have a certain validity in their original context, but outside that, they are hack procedures. And so is clear tube fuel measurement.

Honda's direction to simply measure the float's height using their special tool is very worthy. It works, it's simple, and it's all that is needed. And it's accurate, certainly far more than the clear hose procedure, a method that has no reference point, no standard. And note that Honda has never promoted it. Never, in fifty years in this business have I seen it in a Honda publication.

The clear hose thing actually originated with Mikuni carburetors. You want to know how bad early Mikuni float valves were? Just look around for any Yamaha triples or XS1100 fours. Not finding them? That's because their roller bearing crankshafts all bit the dust long ago due to the bike's crappy OEM float valves. 2 Seriously. Early Mikuni carbs' floats and float valves were so bad that Yamaha came up with this clear hose deal. Kawasaki in the early days also used Mikuni, and they also promoted the hose method.

Do your float measurement the Honda way, using the Honda tool, and the Honda method (right side up, as Honda's 1960s and 1970s publications show it). You can't go wrong. 3

Notes:
1 Only if you are using nothing more than a simple ratchet for tightening should you ever put thread locker on a fork damper bolt. And the oil in the cylinder thing has been superseded by the leakdown test since the 1940s.
2 Due to crankcase oil becoming largely gasoline.
3 On the GL1000, be sure to avoid the notches when using the Honda float level tool. By the way, Randakk's float measuring tool, because its short length depends on those notches, will result in an incorrect measurement.