Don't worry about talking hypothetically or using the phrase SWIM, there isn't any problem with it.
My answer is: most likely it is far less effective. By then (after 14 hours) the acute tolerance from taking the acid is much stronger than the synergistic effects would be expected to be for compensation. I cannot help but wonder about the situation that would warrant such a timing of drug-taking, but maybe during festivals or home-hosted long psychedelic weekend parties this is possibly something desirable?
An important addition to the answer is: results (aka your mileage) may vary. Some people take acid two days in a row and get little tolerance effects. But most do. It is unwise to assume too much tolerance and potentially overshoot your acceptable intensity with high doses though it is also a shame if extremely apprehensive late-redosing is attempted.
My advice is: take a normal dose of 2C-B if you want to try this, not a higher one. If there is little cross-tolerance and a lot of synergy then you are in for a treat but not an overwhelming and bludgeoning one (granted 2C-B is gentle by nature). If there is a lot of cross-tolerance and you are already coming down too much from the acid to have real synergy it would be mild but you then know your reaction for future reference and can gauge if another 5 or 10 mg would be needed.
Also, check how you feel after those 14 hours. If you feel peaceful but energetically drained the 2C-B may feel naggy like trying to give you a psychedelic little wave that does not feel worthwhile at all. A proper acid trip often gives the feeling that it provides everything that was asked for. If you want a longer ride I suggest redosing acid at an earlier moment to prolong the acid plateau.
Experienced trippers may take all of this for granted and drop an unreserved high dose of 2C-B accepting the possibility that it will be an extra turn and peak in the roller coaster ride. But if you were one I would definitely not expect you to ask this question here, if you catch my drift.
