The LMS chip has a PLL that can tune down to 30 MHz, but it also has an NCO that can take it further down to DC or so. But this is handled by the hardware and the driver and applications need not concern themselves about it.
The only thing to remember is that when the NCO is used to tune on HF, we must have the bandwidth opened up, hence the need to set 60 MHz bandwidth in gqrx.
There are many posts on this forum with screenshots showing gqrx working on HF.