By allowing the other to simply move-away

By allowing the other to simply move-away one is essentially giving up the home court advantage.

If you lose local jurisdiction, then legal costs, in addition to lodging and travel costs, will tremendously increase for out-of-state trials.

If the other parent is served in the local jurisdiction this will also buy additional time for negotiation (perhaps mediation/therapy) and settlement, while you establish further ties to your child.

The jurisdiction choice is literally in your court now. After the other sets up residence, it is most probable (for $upport) that you will have to respond and travel out-of-state, in addition to dealing with the problem of loooong distance custody (+ more expensive than lawyers).

Think it over VERY carefully; got to bite the bullet eventually – pick the time when it offers the best advantage in terms of strategy.