Currently the integration is able to add custom attributes from position data to the device_tracker attributes, so I would like to have a similar or an extension of this functionality to include data that are not part of the attributes array.
For example, it would be useful to have data from the positions api response like speed, course and any other available data as attributes.
I know that there are a few sensors like speed or altitude, but I think that this would make the integration even more flexible.
I had a Traccar server running thru the Traccar addon for a while and it had a huge number of things you could send back into HA. I think I just pulled in speed and battery, but there were more things available than reasonable.
Did you look at the addon or a docker install of a Traccar server?