How can I filter a custom 2-pin device when the first pin is attached to a floating net.
Assuming you have a custom, two pin device called "mydev" in a DEVICE statement, you can cause Calibre to filter it like it were an unused other type of device such as a resistor, by using the LVS DEVICE TYPE statement, coupled with the RB and DEVICES arguments to LVS FILTER UNUSED OPTION, as shown in example here:
LVS DEVICE TYPE r mydev
LVS FILTER UNUSED OPTION..rb DEVICES mydev
This does not make mydev into a resistor, it just makes Calibre treat it like one you would filter out.
The RB function says to filter "resistors" (in this case "mydev") when one pin is floating.