* And fallback to serial if not. Unfortunately this can only be queried at
  run-time it seems.

* reshGetVal returns non-NULL pointers, always.

* The used field was relevant before resource handles became generically
  treated in resource_handle.c.

* These modes do not all work immediately but will later on.

* Without the additional check, the level value scaling factor might
  be chosen incorrectly and cause the scaled value to overflow a
  32-bit integer.