SubGHz radio frequency

I’m in the US. Now I might be mistaken about this, but my belief is that the free Sub-Ghz frequency here in the US is 915MHz. I assume, since the product is coming from CZ that the default frequency in the FWs will be 868MHz (or something). Is there some way how to change the frequency of the radio? Preferably without creating custom firmware (as I assume with your indiegogo campaign you will attract customers from outside CZ/EU).
For myself, I can create custom firmware but I didn’t yet find how to do it – the default gateway sources on github do not show anything w.r.t configuring the radio. I’ll be happy if you can send me some pointers.

Hi yendo,
for indiegogo for US and other markets where 868 MHz is forbidden we assembly radio modules with STSPIRIT1 915MHz module. This module is different by hardware means because the antenna and other radio parts are specifically tuned to this frequency.
Regarding the firmware, there has to be a small radio initialization change. But we would try to keep it automatic so customer don’t have to even think about it.

Hi Martin,
thanks for your reply.
But is there something I can do with 868MHz modules now when I already have
them? When I was playing with some other modules for subGHz (I think
lorawan, but not sure now), I seem to remember that someone told me that I
can set 915 module to 868. Of course, there is no free lunch, so the
reception will be/would be worse because of the mismatched antenna length,
but it should work (I was told). I don’t recall if I tested it or not,
probably not.
Do you think something like that would be possible for spirit1 as well?

It would be possible to get it working, but we cannot guarantee the signal sensitivity.

Today I’ve seen that Adafruit sells some 900MHz generic radio modules. So it is not perfectly tuned but they have similar sensitivity at 868 or 915 MHz.