Please write in english.

I thinks such feedback/request should go to plugin's bug/issue tracker.

Disclaimer: I like the fact that additional features for GLPI are possible via plugins: this makes the GLPI core less bloated.

Why integrate a plugin into the GLPI Core? If the plugin does the job there is no need to make it part of GLPI.
If you think the plugin's features should be integrated into GLPI's core: please explain why it should be, which advantages it would brings, why the plugin-solution is not working (or badly).

It seems the v0.90 includes such feature.

I don't understand: you want the value to look for to be typed in a <textarea> instead of an <input type="text" />?

Since the dropdowns are now (since v0.85 I believe) searchable, If you want to set the location to "Room 3" you can type "Room 3", the dropdown would then filter out locations whose name does not contains "Room 3" while keeping the intermediates/parents of locations whose name contains "Room 3" also keeping the hierarchy.

I find a single input easier to use than a succession of inputs.

Disclaimer: I like the fact that additional features for GLPI are possible via plugins: this makes the GLPI core less bloated.

Why integrate a plugin into the GLPI Core? If the plugin does the job there is no need to make it part of GLPI.
If you think the plugin's features should be integrated into GLPI's core: please explain why it should be, which advantages it would brings, why the plugin-solution is not working (or badly).

Having the object's name in the <title> page would help when dealing with many browser tabs.

Disclaimer: I like the fact that additional features for GLPI are possible via plugins: this makes the GLPI core less bloated.

Why integrate a plugin into the GLPI Core? If the plugin does the job there is no need to make it part of GLPI.
If you think the plugin's features should be integrated into GLPI's core: please explain why it should be, which advantages it would brings, why the plugin-solution is not working (or badly).

Please see CALDAV server support which is a more generic way of doing the same thing (and thus profit to more setups).