To avoid all those cumbersome numerals, I think they should assign each different warp speed an arbitrary name based on a flavor, instead of thinking in terms of numbers. More decimal points would be expressed with different flavor combinations.
"Ensign, set course for Alpha Centauri, Warp Factor strawberry-chocolate-pistachio-curry-garlic-sardine-bubble gum. Engage!"
And as a bonus, the replicator makes you a very special dish based on that flavor combo.
Kor
They tried that, the ensuing argument over which flavors were ranked higher than others nearly led to civil war.