Why do you have to press "v" to get a via ?
Most decent programs place them automatically as you change layer !
"V" is the keyboard shortcut to change to the selected alternate layer
and drop a via. The layer pair for vias is a user option. It defaults
to component and copper but can be any two layers.
The top and bottom layers are bound to PgUp and PgDown, with inner
layers (up to 8 inner) bound to F-keys (additional layers beyond 10
total don't get dedicated keys). Changing a track's layer with Pg-x or
F-x does drop a via, as expected.