I have abandoned my plans to use MMIC chip switches, they seems too fragile for HF. A simple RX protection circuit attached to the PA output protects the BPF input switch from high energy. Series and shunt PIN diodes are used, controlled via a pair of PTT/PTT_NOT signals.
So far this configuration can handle 5W safely. If more massive overheating on D1 occurs a blob of solder acts as primitive heatsink on the prototype board,