Interactive Brokers - all eggs in one basket?

@hedgehog , I transferred those shares to Pf 4-5 years ago, long before I had even heard about IB. Yes, I will pay about CHF 100 fees to sell in about 20 years. I can live with that.
Swiss Stamp Duty (I translated it from Stempelsteuer or Transaktionssteuer) is charged equally when buying and selling shares in Switzerland (0.1 for CH shares, 0.15% for foreign shares). That’s why I wud imagine it a loophole to transfer shares from IB to Postfinance and thereby avoid the Swiss Stamp Duty (which is a relic from the First World War btw) and the tax man don’t like loopholes (nor people using them).