Is it possible to show the Xbox download in MB / s and NOT in Mbit / s?

Is it possible to show the Xbox download in MB / s and NOT in Mbit / s?

Very unlikely.

Here's a table where you can look for yourself: https://www.speedtestx.de/tabelle-datenrate.html

You just have to divide the number by eight and you have it in MB / s. Or just move the comma one place to the left. That is then wrong, but approximately correct.