dont prune leaves on an auto! Only prune leaves that are:1) laying on the soil 2) have become completely necrotic (this doesnt include just yellow tips; once a part of the leaf literally has gone brown and crispy, then pull just the dead part off to reduce bacteria/fungi)
I really would not recommend pruning for any other reason, the leaves are green for a reason, they contain chlorophyl which captures light to make sugars, these sugars are transported around the plant to where the plant wants to use them, so fan leaves DO increase bud size and the general health of the plant.
On a photo strain, there are growing techniques during vegetative growth where pruning is utilised, because the veg phase can be prolonged until the plant has the desired structure. But an autoflower is a ticking clock from the start. If space is a problem, use lst or scrog or just use less plants from the start. in a small space, less plants = more good bud. (ive also recently heard good results from early topping, but this seems contraversial still, im gonna top one of my next autos for test)