More parts? Are you referring to the use of beads to help protect the bridge patch. I don't understand why people think changing strings on a through bridge is a hassle. You don't have to remember how many loops etc. like you do for a tie bridge. I'm not sure what damage you are referring to either.
I think the biggest complaint I've heard is that it's hard to get the string to come out of the soundhole since you have to insert them through the bridge into the body. But all you have to do is twist the string a couple times and it shoots right up towards the top and makes it a snap to get hold of. Plus I drill the holes at a slight angle towards the soundhole to help direct the string in that direction. I love this design. I'm not an engineer but I believe it puts enough tension on the saddle to adequately drive the soundboard without the extra tension that is applied by a standard tie bridge. Less chance of having a bridge pop off (which shouldn't happen anyway if the uke is properly built and not abused by leaving it in a hot car etc.).
All that said my second choice would be the tie bridge. I don't like the slotted style like that of a vintage Martin.
I like the string thru the bridge method myself,....pretty easy once you've done it just once usually. Like you mention,...the bridge a lot less likely to ever pull off!
The bridges can also be made lighter and more responsive, since it is relieved of a lot of the stress of string tension. (not always seen though, not sure why?)
One thing i do is make a set of thin ebony washers (bottom of the soundboard protectors, especially for a spruce soundloard). I cut a small section of ebony from the stewmac binding material, and round it up freehand on a foredom flex shaft to about round shape and drill thru the center just a bit wider than the string for that hole. I also round off the edges and sand a little for a cleaner look. (not important, but i'm a bit picky)
These provide hardness at the knot end, and spread the force over a wider area of the top so they don't dig in over time. If you want to avoid having to deal with them on every string change, you can use CA glue and attach them permantly to the underside of the top.
If you do that, the way i do it is feed a piece of an old string thru the bridge hole on top of the uke until you can retrieve it thru the soundhole. I then slip one of my ebony "washers" onto the string and push it into the sound so that i can tie a knot onto the string end.
Next i apply a bit of petroleum jelly around the actual knot and on the string just off the knot for about 1/4" or so, in order to create a barrier to keep any CA from sticking to the temporary string you'll use to pull the ebony piece up againt the underside of the top.
Once the knot end of the string is lightly coated, i slide the ebony washer back against the knot. Don't go crazy with the jelly, as you want to keep the ebony flat surface free of petroleum jelly in order for the CA glue to take hold. Usually a little will end up in the hole,...which is good, as it keeps the glue out of that area and will be easier to free the string once the glue sets the ebony to the top surface.
Anyway, i then place a small drop of CA glue on a small plastic baggie, and pull most of the slack out of the string so that the ebony washer is near the soundhole. (usually a good idea to have a plastic baggie around the soundhole if you tend to be messy with glue!)
Last steps are to place a little CA glue on the ebony washer and spread it around evenly to cover the entire surface. I use one of those pointed nylon toothpics with the floss built in. Then in one motion i guide the washer into the soundhole (left hand) while pulling at the string at the bridge, (right hand), and pull the ebony washer up against the underside if the top and hold for a few minutes or so.
After a few minutes i carefully push the string at the bridge end back thru the bridge hole. Usually i cut it off first so only a few inches have to go back thru the freshly glued area. It's also easier if you left a foot or so of string on the other end of the knot, as it gives you a bit of a handle to pull the string back out thru the soundhole. Not required though, as you can simply push the remaining string out of the bridge with a small drill bit held in your fingers, or with a sewing needle with the point flattened.
I save all my old strings for jobs like this. The knotted string guides & centers the ebony washer exactly where you need it to be, and the bit of jelly keeps the CA glue from sticking to the knot or string.
In the end (after all string knot ebony supports are installed), you never have to fool with them again, and the softer tops are protected with a mini bridgeplate of sorts.
