WL1807MOD: EXT_32K required if BT is not used

We use WL1807 without BT (it does not have).

The datasheet shows in figure 1-1 that EXT_32K is only connected to BT MAC/RF part of the chip/module.

Is it allowed to strap this signal to GND or VCC? (so not providing a 32.768k sleep clock)
Or must this CLK also be active/valid running when only using WiFi?