jem7sk -
Yes, AIO = all in one - trying to do 3 things in one process, has to have its limits..
I think even Optimum has one called GPS = Glaze, Polish, Seal...
None of my Clients have ever wanted just that, but many people really want just that..

It is convenient, less money than many specialized products, less time spent doing the work.. Then, there are the trade offs, right ?
What do YOU want to See, everytime you look at your vehicles ? This is the ultimate question..
To maintain anything on there, it is always best to use a wash soap type of product that does not want to work at stripping off the LSP you put on there, right ?
So, find a mild one that does not do that and this will help the longevity..
When does it need it again ? When you look at them, and they do not look like - "What YOU want to SEE, everytime you look at your vehicles"..
Of course, the more you can keep your vehicles in the garage, covered, etc., their paint will always look better longer, the less you rub on them, the less chance you have, to introduce things that take away the clarity you once had, so think about that part too..
Personally, since they invented CarPro Reset, It is all I ever use on my 2 personal vehicles, and for sure on any Client`s vehicles that have been coated..
It just works great and does not seem to take away the product...
I know, there is no fancy "LSP-Strip-O-Meter Measurer" invented, yet, but perhaps someday, in the interest of eh-hem, improving the craft, and not so much of eh-hem, Marketing, someone may invent one..

Until then, your/our eyes are doing that just fine..
When Opti-Seal came out, I think they also made something called Hyper-Seal, but for some reason, that product went away.. Perhaps because it was insanely expensive?? I dont remember..
I have experimented with Opti-Seal and it seems to offer some protection and improve the gloss; the length of time, of course will always be different for Everyone, because we all have our own things to deal with for our vehicle/s.. etc...
In my own experiences, I really like the dirt releasing properties of Coatings more than anything else, and the fact that this condition can last a long time, before it goes away.. I know from personal experiences that my 2 coated vehicles can go 2,000 miles from Northern California to Texas and when I get there, they do not even look like they went anywhere, except for the bugs that hit the glass..
Then, I might wash it, or not, and go drive the 2,000 miles back to CA and look, the vehicle is not really trashy dirty or anything, except for the bugs that hit the glass.. And of course, clean up with Reset, really easy..
That`s all I got for ya !

Dan F