I’ve found the Pololu modules fine with ASK and FM radio modules; the switching noise depends on the load, so you have to pick one that has the right load range.
Yes, noise is a risk. Especially with radio receivers. If the circuit of the radio has no filtering on the DC supply, then replacing batteries with anything can decrease sensitivity and therefore range. This might not be a problem where you are; if you’re close to a transmitter.
Perhaps you could probe the circuit with an oscilloscope to see what level of power supply noise is there now, with batteries. This noise will depend on demands from the CPU, the internal resistance of the batteries, the spring contacts, and the wire from the battery compartment to the circuit. There may already be filtering so as to avoid the wire from the battery compartment turning into an antenna. There may be a switcher on the circuit already to ensure 3.3V is available from nearly flat batteries, or bumps on dirty contacts. If so, you might not need to worry so much. Have you a photograph of the circuit board you can show?
Wiring a 3.3V LDO might be more to your liking;
if the current is enough. May need heatsink.
Watch out for the USB cable radiating RF; if that might happen, stick a choke, such as a clampshell ferrite core over it. This improved the sensitivity of my kitchen radio when I changed the power supply for it.