yeh...this is very similar to where I have ended up..I presume those are teflon or similar strips on the inclining guides.
I added guide posts inserted into the rear horizontal....adjustable with a bolt lock and drive on is a breeze...basically the boat cant end anywhere except the middle..unless you try really hard!
As my boat has a running plank the guides actually feed to roller height so there is not an "edge" probably not so much a problem if your hull has a V shape keel
The main difference is that the bunks are more central on the trailer so that they only engage and stabilise the hull towards the end of loading...or disengage near the start of unloading..
The bunks were made in 2005 and are redgum! covered with marine carpet , very simple....I have found the odd wash and spray with silicon helps keep them clean and slippy enough.
I like the safe steps at the back and wire mesh at the front of the trailer.
Again in my case we use the mudguards for access ..and it pays to have some sort of anti slip on the top.