I grow nothing but autoflowers... and they don't like high stress - not topping, not fimming, not super-cropping, not transplanting... they want to go into the soil or hydro and do their thing... so LST is the ONLY technique you should consider with them. While some people have successfully done higher stress techniques with them, I'm convinced they were all basically lucky. The danger is that they will not have time to recover from the stress before they're wanting/needing to move on to a new stage of growth - and if they can't recover, their progress is cut off for them. If you top them, for example, too close to the time they're wanting/needing to go into pre-flower, they may never set their buds. The problem is that you don't know precisely when your auto is going to do what... some autos go into pre-flower in week 3... others might not do that until week 6... if they could talk to you and TELL you what their schedule is, then maybe you'd have a shot at success... but they're plants.
Stick to LST! You can scrog if you want... you can sog if you want... but no topping, no fimming, no super-cropping...
Good luck!