my utility trailer had a crank up welded in the A frame , when it failed and had bent and broke welds I had it cut out and had a swing up welded on and no longer have the issue.

the 4-H trailer had the same issue but a touch more clearance and was a bolt on I have it with a set of spacers I made to get it high enough to not hit.
luckily it didn't break any welds .

one thing I found is most Jacks have no good way to grease them , I drilled a hole and used a press in zert fitting about a half inch from the top of the tube this seems to be working well to keep the jack from freezing up inside . a few dimes worth of grease can save a lot of money in time and replacement later.

One thing to remember about a single axle trailer is the ability to turn it around by hand on a narrow road should you get yourself into a bind. Difficult to do with a dual axle.

ol' dad

Spare tire, bottle jack, grease fittings on axle bearings and jack should be required. Spare hub and bearing sound like good idea too. Like the swing up jack idea too.

Like this tip!

I was looking for something similar and ended up buying a used Ice Castle fish house/toy hauler. It wasn't much more than an enclose trailer and I can camp in it year round. It's deprecated enough that I can sell it in a few years if I want and get most of my money back. Another addition is since it's 12', I can get a life time license on it so no buying tabs for it every year.

Tandem and get Dexter axles if your ganna be hauling weight