$decode(%var | &binvar, amubt, N)

$decode ignores the N chunk parameter. Both v7.52 and current version display in red the entire length 300, while v6.35 displays the red string as 016017018019020021022023024025026027028029030

Code:
//var %switch m , %original $regsubex($str(x,100),/x/g,$base(\n,10,10,3)) , %b $encode(%original,%switch) | echo 3 -a original: %original | echo -a encoded: %b | echo 4 -a $decode(%b,%switch,2)