The Swiss Arms rifles are already perfection. No need for bolt on plastic front sights and AR butt stocks.
I don't know about perfection. Depends on what your idea of perfect is and what your intent for the rifle is. Don't get me wrong, they are one of my favorite rifles and I have owned many of them but I don't think they are perfect.
For example, I'd prefer a non-reciprocating charging handle on the left side. I have to reach over or under with my support hand to work the action, like an AK.
The "back up" sights on the flattop variant suck. The front blade is too fragile and the rear is a tiny leaf sight that you have to dig out of it's slot in the top rail.
If you get the non-flattop and you'd like to use an optic, you have to use a bolt on chunk of rail. Usually a cheek piece is also required in order to achieve a correct cheek weld due to the fact that your optic must be mounted high enough to clear the irons.
There is no free float hand guards available at this time. If you want anything on the front of your rifle you must use either the plastic hand guards with a bolt on rail or the very expensive B&T quad rail. After using both, I'm not confident either would be suitable for mounting any kind of aiming device (IR laser). There is simply no way to hold zero. Both would be sufficient for white light.
A mediocre flash suppressor is permanently part of the barrel and does not allow any other options.
The stock, along with sloping down and requiring a cheek piece for optics, is not adjustable for length of pull. If I want to shoot with gear on (vest and armor) I'm stuck with the length. There is the option to purchase the aftermarket three position stock for around $500 CDN.
If I want to sling the rifle, in it's current form, I'm relegated to some sort of "HK Style" hook attachment points. Personally, I prefer a two point sling with my rear point on the butt stock and the front point at the rear of the hand guards. There is no point near the back of the hand guards. My choices are WAY up at the front on the gas block or on the back of the receiver which turns my two point into more of a single point and the rifle into a pendulum.
These are just some of the things I dislike about the rifle. I still own them, because despite all of my points, they shoot extremely well and they have a solid design under the hood.