There is not builtin mapping for d alone, it has to be followed by something to be processed. This is why wait time for it is infinite.
There are two layers of mappings for every mode: builtin and user, with user mappings shadowing builtin ones. For every input one of this is the case (if <wait>
wasn't specified):
- Exact user match. No timeout. User sequence is dispatched.
- Partial user match and exact builtin match (t, n). Timeout waiting for a next key. If nothing was entered, builtin key is dispatched.
- Partial user and builtin match (d). Infinite timeout.