I'm basically designing a quadrupedal digitigrade alien, which has evolved from a predominantly arboreal animal into a predator with more cursorial adaptations, capable of running fast, but still being able to climb well. It's 4 limbs possess 2 opposable digits and 2 middle digits used both for running and for climbing, having a structure that remotely resembles a zygodactyl bird's (that is, one opposing digit on each side, but these are not used for running). My original approach was for its front limbs to engage in a knuckle walking pose, especially in order to conserve its claws, but apparently that would make it unable to run fast, maybe due to low stability.
My second approach would be to have very flexible digits with joints capable of bending in an angle near 180 degrees, similar to the flexibility of the fingers from the images below (nemesis 2nd form, resident evil 3 remake), which technically would allow it to still be able to grab without staying in the way while running.
My question is: is it viable for my alien to have this kind of flexible digits in order to adapt well for both running and climbing? Are there better adaptations to allow for this kind of movement? Preferably I'd rather avoid the retractable feline claw path , since it doesn't seem as good for climbing as it is for running, and lacks the opposing digits.
Aditional info: it's sharp claws and front limb strength are its main tools for subduing and killing prey. It's world has earth like conditions with slightly denser gravity and its habitat is composed of large open plains with sudden cliff-like elevated regions spreaded across the region, which are the reason it still needs to be good at climbing (uses these as mating grounds).