My $0.05 I wrote a lisp that just asks for the offsets includes left and right by using a -ve the input is a simple string either space or a comma input.
eg 12.3,45,-12.3,56 or 123.3 46 52 -12.56 -52.68
It is split into a list of multiple offsets and just do it. The feet part could be added fairly simply by adding a defun that looks for the - and returns the correct string for the offset command.
This is an old one will try to find the newere version its at home.
(defun C:MULOFF ( / obj s off)
(vl-load-com)
(setq obj (entsel "\nSelectObject"))
(setq s (getpoint "\nPick Offset side"))
(while (/= (setq off (getreal "\nEnter offset or Enter to exit")) nil)
(vl-cmdf "_.offset" off obj s "")
(setq obj (entlast))
)
)
(c:muloff)