Yes sprint speed as the base speed is good, also try to make to have a different gravity force after the character reached the highest point of the jump and stuff like that. Actually there is a great GMTK video about it named "Why does celeste feel so good to play?" that could help you see what I mean ahah
Platformer controller is really difficult to implement, but if you want a better game feel, you should definitely check this kind of stuff :)