The whole point about selecting a distance-marking (past-tense ) form rather than an unmarked (present-tense) form in a conditional sentences is to distance the possibility in reality.
It is not impossible to use an unmarked form in a counterfactual situation, but only in very restricted contexts.
A: Mark says he is a colonel in the Secret Service.
B: If he's a colonel in the Secret Service, then I'm the Pope.
5jj: If keannu doesn't ask a follow-up question, I'll eat my hat.
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