Why
The only reason that symbolic arrows aren’t more widely used is the difficulty of activating them with a regular keyboard. Stenography allows us to make this trivially easy. Think of the pretty documents you could write, or the silly puns that you could make. All that’s ← is for you to come ↑ with ideas of how to use them!
How
The strokes are defined based off of Plover’s default arrow movements. For moving the cursor in Plover, you tend to use STPH- plus RPBG which acts as a WASD-like cluster. Quite simply, you use the keys like an arrow keypad, such that R is left ←, P is up ↑, B is down ↓, and G is right →.
With this dictionary, instead of moving the cursor, you want to create arrows. For this, the left hand makes the shape of an arrow with KPR- and the RPBG cluster. Additionally, if you press two directions in different axes, you will get the diagonal arrow. For example, KPR-RP is the up-left facing arrow (↖) because R is left and P is up.
Those are the most intuitive strokes in this dictionary. You also get bidirectional arrows: up-down ↕ is KPR-PB, left-right ↔ is KPR-RG, and finally two arrows, one left and one right ⇄, is KPR-RBG.
Bonus: R*URPB (return) gives you ↵