How to overcome 3.2 mm x 2.5 mm smd crystal pinout differences
Connecting separate pads of the crystal is a bad idea, but you don't need to.

It's a bad idea because (on some packages) the metal case around the crystal is connected to the spare pins, and so connecting them would short the crystal through the case.

You don't need to because the pinout is standardized for this package—the crystal is on pins 1 and 3. The datasheet you linked for the ECX-32 is confusing, because it shows the schematic from underneath, but it still follows the standard.