Trying to envision the actual technique with the 2x4, but in general such adjustment procedures are not uncommon, especially with door adjustments. Years ago bending the upper door frames by hand/body pressure was a procedure in some of the GM service manuals, although I know that technique was also used by Ford techs as well.
There is some lateral movement in the hinges on DT Rams and normally more than enough to compensate for minor misalignment. But some with body shop experience might just find is quicker to use a 2x4.
Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 038188 miles.