Hi there and welcome to the forum.now I hope you have very good knowledge of electricity and yes your concern is completely valid. When running long lines from wall push buttons to the main electrical panel (runs that can easily exceed 5 to 15 meters depending on the room), the cables literally act as antennas.
The control inputs of many smart relays (S1/S2/COM) are highly sensitive and use very low pull-up sensing currents. With long, parallel runs alongside 230V AC power conduits, it is common to induce parasitic capacitance, which creates enough phantom voltage for the module to register false triggers (the relay toggles, turns on, or turns off on its own).
Without precautions: If long parallel cables are used without shielding or filtering, reliability drops drastically, and you will experience random phantom activations (especially when heavy appliances switch on elsewhere in the house).
With proper installation: It can become totally stable, but it requires careful attention to wiring type and physical panel layout, since the T2 was not natively designed out-of-the-box for very long control runs (unlike industrial PLC or KNX systems).
To minimize electromagnetic interference (EMI) on long runs heading back to the electrical panel, experienced installers strongly recommend:
Shielded Cable: Use overall shielded twisted-pair cables (such as LiYCY or instrumentation/data cables) for the connections between the wall push buttons and the S1/S2/COM terminals.
Grounding the Shield: The drain wire or shielding mesh must be grounded at only one end (preferably on the electrical panel side) to safely drain any electromagnetic interference picked up along the way without creating ground loops.
Physically avoiding routing these low-power control lines tightly bundled inside the exact same corrugated conduit or shared channel alongside heavy power cables for long distances whenever possible.
Routing and Separation (Crucial): Physically separating the push button conduits from high-power supply cables is the most effective preventative measure.
RC Snubbers: If micro-inductions or bounces persist despite using shielded cable, placing small RC snubber networks / spark-suppression capacitors between the S1/S2 inputs and COM can help absorb induced voltage spikes. However, because the T2’s S1/S2 terminals handle internal low-power logic referenced to its own circuit, the best defense against phantom voltage remains a clean, low-impedance switch closure (ensuring the contact pulls solidly down to actual COM) combined with proper cable shielding.
As an extra tip:
If you are designing a brand-new installation with a centralized star-topology in an electrical enclosure, consider whether an exclusively Zigbee-based ecosystem like Aqara is the ideal fit. Many users seeking absolute reliability in a DIN-rail home setup prefer natively wired gateways (such as DIN-rail Ethernet modules like Shelly Pro, Home Assistant / ESPHome setups, or dedicated bus systems), reserving Aqara T2 modules for decentralized placements (hidden behind wall switches where cable runs are only a few centimeters long).
I hope this helps you but my opinion is to check an electrician to guide you better.