Hide empty conduit invisibly in plaster facade

Hello everyone,

does anyone know possibilities or have ideas on how to realize that there are concealed empty conduits on the exterior wall that can be "opened" and used when needed? So the end of the empty conduit. Wood fiber insulation boards are to be installed on the exterior wall. Could one simply cut the empty conduit flush and seal it with a blind plug so that it can be easily plastered over? But then there is still the problem that it is very difficult to find this empty conduit later. Or would you rather install something like the Kaiser Universal device carrier at such a spot? I just want to make the empty conduit invisible, but which I can open if needed. I am very grateful for suggestions/ideas.
Thank you very much

I am not very familiar with it yet, but my electrician made me the suggestion a few days ago, since I am having a 5-core power cable installed for a possible electric awning later on. He said you could install a flush-mounted box in the exterior wall where there is then a cover with a chip inside, and the box could be easily found later on. However, he couldn't tell me what it would cost. Regards Andy

Or plug in a magnet ;)