Whether you are painting stucco or wood siding back rolling is always one of the most helpful ways to give the longest lasting protection and best finish. For stucco we always back roll on the finishing coat this lets the roller push the paint deep into the pores of the stucco making for the strongest bond, preventing any chance of paint peeling threw standard ageing. Back rolling also helps fill small cracks and smooths/ evans out the surface to make it look more uniform and cleaner.
When it comes to wood siding back rolling it is also done on the finishing coat and also does the same to the wood as it does for stucco only also it provides a stipple texture to the wood. This texture actually makes the paint stronger and longer lasting because you can apply an even coat of paint thicker, this keeps the property safe from UV Damage and prevents fading. Other tips for having a long lasting paint job is to use light colors and have a higher sheen of paint and lastly prime everything before applying two coats of quality paint.