A Model with Segmented Bond Market

Regarding the tag, see Deterministic model with linearized equations

I am not sure I understand the full logic here. The ZLB is an occasionally binding constraint. You hit it whenever a shock brings you there. You seem to be suggesting that you want the central bank to deliberately choose a value for the interest rate instead of following a Taylor rule. That seems more a matter of specifying an exogenous process then of an endogeneous constraint.