The link does not work, it just goes to the famaga site.
Can you link direct to an RS page, or give a part number?
The only terminals I know which electrically connect to the steel rail are earth terminals. If that's what you mean, as long as you use the appropriate size & current rating they should be fine.
I would suggest you always use the "heavy duty" / 15mm deep DIN rail, it's much stronger than the basic type. The thin stuff can crush under the pressure of some screw clamps and things come loose.
eg. This style:
As you mention home automation..
Have you seen the size of such as Fibaro modules? They are tiny; this type of thing:
**broken link removed**
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I have one here; 42 x 35 x 16mm for such as a light dimmer, one 3KW switch or a dual channel switch rated 10A total..
And you can now get wall switches with Z-Wave built in from around £20, so no extra modules needed at all.
Z-Wave is superb, as everything is two-way - use a web interface or app and control devices or lights.
Plus, when you operate them locally the status changes on the web interface or app, unlike most other systems.
And it all makes work together, there are no tie-ins.