slick way to turn Harbor Freight cheap-O folding trailer into small boat trailer?

Actually, was thinking of one of these big money alum folders.https://www.amazon.com/Ultra-Tow-Folding-Aluminum-Utility-Trailer/dp/B071XZ2ZCY/ref=sr_1_3_sspa?crid=3NDWZI2IH5AZD&keywords=folding+trailer&qid=1690922902&sprefix=folding+,aps,1039&sr=8-3-spons&ufe=app_do:amzn1.fos.2b70bf2b-6730-4ccf-ab97-eb60747b8daf&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1 I got other schemes for the folder (flyweight enclosed camper/cargo), but still want to retain the folding feature if possible.

I'm thinking to install boat bunks I'd put a few pillows over the frame, then place boat hull on pillows, then bolt legs to the bunks, then push bunks up to hull and clamp legs to trailer frame, then drill holes for bolts through legs and trailer frame, then install bolts to lock everything in place.
Are these trailers suitable for small boat trailers (with mods)?
Looks like tongue-frame folds so I THINK the whole trailer could tip back while still attached to tow-car, which might be handy for boat ramp operations.

Not sure what sort of boat, but figure small sailboat or alum runabout.

Yeah, I know I'd need to upgrade to waterproof trailer lights. Can I also upgrade to submersible wheel bearings?

 

Attach some "posts" to the rear corners of the trailer frame. By posts, I mean some wood or aluminum posts that rise perhaps two feet above the frame. 1.5 inch wood will do the job. Mount the lights atop the posts. The posts will also be useful when backing the trailer down the ramp when the trailer is empty. The posts are visible while the trailer frame may not be, depending on which towing vehicle you are using. The posts, if padded, also help keep the boat in the right location while loading. Very handy when loading or launching on windy days.

The wheels have seals that are primarily for the purpose of keeping the wheel bearing grease where it belongs. The seals are in the inboard side of the hubs. Those seals,when in good shape will usually keep the water out. One of the problems is that the hub becomes warm when driving down the road. The water temperature will be lower than the hub temp. When the hubs and wheels are immersed during the launch process, thermal difference can set up a modest suction which can cause the ingress of water into the bearing cavity of the hub. Make sure that the seals are two way types. Not all grease seals are made that way.