PEX-AL-PEX to replace gravity radiator main?

Kyle_6

I am doing a basement renovation and the main supply pipe for the home's gravity fed radiators runs at a bad location through the middle of the room that I am trying to finish (even though all of the radiators are located around the perimeter of the house). I should clarify that the system looks to be piped for gravity operation but I think the new boiler (1990's) has a pump.

Is it acceptable practice to replace a main with PEX-AL-PEX? Given the cost of 1.25" copper tubing these days I thought PEX might be a better option. I would be just moving the main to the perimeter of the house to the new insulated stud walls that I will be framing. The radiator feed/return drops could then go right into the main instead of having to do a semi-horizontal run like they do now.