If you are doing point transformations with the trans function and you need to make that part of a program run faster, you can construct your own transformation matrix on the AutoLISP side by using trans once to transform each of the basis vectors (0 0 0), (1 0 0), (0 1 0), and (0 0 1). Writing matrix multiplication functions in AutoLISP can be difficult, so it may not be worthwhile unless your program is doing a lot of transformations.