I am trying to design the transmit matching circuit for a STM32WL5 QFP48 For operation at 403MHz. The closest thing I have found so far to design advice is AN5457 which provides a procedure, but it seems to rely on a starting point of an output impedance value for a given frequency and output power. AN5457 appears to be the only source for these impedance values and it only provides values for frequencies around the 868MHz and 915MHz ISM band.
Looking at the setup to provide the values in AN5457 I don't hold up much hope of getting a value for 403MHz to follow the theoretical approach.
What is the scale of the impact if I use a matching circuit from the 433 reference designs at 403MHz. I can probably handle a couple of dBs less output and a non optimal DC consumption. Is the 433 setup worth using as a starting point to start a process of measuring output power while changing component values?