@nmcc Your comment is off-topic, but I still want to respond on it.
I believe you are mistaken. The doppler effect will only have an affect on LoRa if you are moving faster than 450km/h. What you are seeing with slow data rates when you are moving is the variation in path fading, causing the FEC to break down.
I’ve been using LoRa trackers for a very long time (look up TTN Mapper). I have found that using the fastest possible data rate when you are mobile works the best. In other words SF7/DR5 in Europe.
Yes I know what the duty cycle limitations are, and LoRaWAN libraries all implement it to prevent breaking the rules. Setting the transmit interval faster will make the device transmit as fast as possible while still staying within the regulations. Depending on the size of the payload this can be as low as every 10 seconds when using SF7. Even if it goes up to once per 60 seconds, it is still good enough for “live” tracking.