Advice for Shelly EM placement needed

I need advice/ideas. Shelly EM and two clamps cannot fit in my box full of wires. How would you install it? Separate on-wall box? How?

Thanks.

[Blockierte Grafik: https://i.ibb.co/qYbk50V/20220202-180832.jpg]

[Blockierte Grafik: https://i.ibb.co/189s8Cq/20220202-180941.jpg]