How does the trailer tow now?
It appears that the boat would be moved back about 8-9". Weigh the tongue before moving anything and after moving the boat back, weigh the tongue again - The tongue will lighten. Move the axle back one hole, then weight the tongue again. Try to get the tongue weight close to what it was before moving and it may mean moving the axle back another hole. It takes trial and error to make it right again.
how about just cutting a few inches off the rear of your bunk boards?
Buy a longer bracket and flip it around. Since I can weld, I would try to make a bracket so you could shorten the bunk.I was just looking at that myself, however when I went out and looked at the bracket still extends out past the transom.
Smart tabs as the OP is going add, do hang down out of the water and water pressure forces them up against the "shock absorber". With the bunk and tab relationship on his boat, the tab cylinder will be under constant pressure if the bunk or boat position on the trailer isn't changed. Maybe Tabman will weigh in?
That's what I was thinking at first but it looks like a "C" channel.It looks like that bunk bracket is just bolted to the trailer. Can you just unbolt it an install it on the other side of that support? That would allow you to trim that bunk a bit and you wouldn't have to move the bow roller, etc.