That's for some slots sadly enough not possible as the payouts have value's which would go below 1 cent.
Some slot's go so low tough. For example
Multifruit 81 (minimum stake 2 cents)
Time travel Tiger (minimum stake 5 cents)
Hugo Goal (minimum stake 5 cents)
@pledman Those only have 1 cent if you reduce the amount of lines (If I remember correctly)
Reducing the lines reduces the experience imo (but others might think differently ofcourse)