You can only create a consensus flag that would verify a proof that the work was only so difficult, this would involve verifying a LOT of shares so it is not extremely likely to be implemented naively if at all.
"If a consensus flag is created to limit computational power, can users bypass or crack computational power constraints?"
Yea they can bypass the computational power but if they submit a share that represents they did this and the consensus flag was checking for it actively, the network would reject such a share. No such implementation exists yet in practice.