Not sure I understand the problem.
IF you are talking about placing the shifter in manual 2nd gear with vehicle at a full stop.... then drive off. The GM design is the 4L60E is in 2nd gear when shifter is in manual 2nd gear position.
The trans will not take off from a full stop in first (1st) gear, then shift to 2nd while the shifter is in manual 2nd gear position
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.