DC - Switch or Checkbox in the attributes list and Value(TXT) input between two values

Sorry, no. Checkboxes are not yet implemented for the Component Options dialog.

This would need the support of a boolean type for custom attributes (Some of the predefined attributes or behaviors are boolean, but this is not yet implemented for custom attributes.)

Not tested but I wonder if a nested IF function will work ? @pcmoor ?

=IF(CURRENT("AttrName")<215,215,IF(CURRENT("AttrName")>270,270,CURRENT("AttrName")))

Try one of these …
=CONCATENATE("Type a value between 215 and", CURRENT("P2_PlafondHoogte"))
… or …
=CONCATENATE("Type a value between 215 and", REPLACE(P2_PlafondHoogte,1,0,""))
… or …
=CONCATENATE("Type a value between 215 and", REPLACE(CURRENT("P2_PlafondHoogte"),1,0,""))

Ie, they never implemented a TEXT() function, but the REPLACE() function converts the 1st and last arguments to String.