Is there a way to convert .ev3 files to .uf2 files?
The .UF2 file format appears to be a fairly compact, binary format for reliably transferring data to "microcontrollers" (i.e. small embedded systems such as the EV3 controller), and is the format used by the Microsoft MakeCode application, recommended as part of the First LEGO League.

The .ev3 file is actually a zip file containing a number of additional files, of which the .ev3p is an XML file representing the program itself.

At this time there isn't an official way to convert .ev3 programs to the .uf2 format, not least because things like custom blocks will need to be re-written in JavaScript, and certain other features may not be currently supported (i.e. data logging beyond console logging, 3rd party sensors, etc.).