Recommend a bike computer please?

Question

Iron

I want to buy a bike computer. The requirements are probably a little non-standard. I assume two usage scenarios:
1) when a smartphone is attached to the steering wheel (I would like to avoid this so that it would not crash) - in this case, the bike computer should be as cheap as possible
2) when the smartphone is not attached to the steering wheel. In this case, the price up to 150 EUR is normal, but still I would like it to be cheaper.
In both scenarios, there is an LTE / 3g connection on the smartphone, and it is always with you, but it is possible that it runs out of power and turns off. I don't want to lose important information.
For the second scenario, I need:
a) minimally convenient navigation
b) calorie counting with export to myfitnesspal
c) the ability to quickly remove the bike computer from the bike so that the bike can be thrown on the street, albeit with a fastened lock
. Recording tracks and the like, popular among those who are fond of bikes, is not necessary. It is optimal if the recording of tracks (more precisely, their transfer to the manufacturer's server!) Can be somehow disabled (if anything, there is root on the phone, and in extreme cases it can be firewalled). And so Google, Facebook, myfitnesspal, and a bunch of other SaaS are already spying on me.
For the first scenario, only calorie counting is needed with or without export to myfitnesspal (I can add it with my hands as a last resort), because. navigation will already be in the phone, and the ability to quickly remove the bike computer.
Of the additional features for which I especially do not want to overpay, but it would be convenient if they were in the bike computer:
Distance, travel time, speed, and cadence recommendations (like cycling too fast can be harmful)