pjs_ch

I've been having debate with partners about what happens (no opponent bidding) after 1♥ - 1NT - 3♥ 1♠ - 1NT - 3♠ and the question is when I bid 4♣ is that (a) a potential trump suit, or (b) a cue bid in support of partner

Pass every time. In second seat, pre-empts should be reasonably constructive as one of the oppo has passed. This suit quality gets nowhere near what partners would expect. Overall high card count doesn't affect this.