I have a 4-bolt on my 89 SWB. I normally pull a purpose built (camping) 4X8 trailer with electric brakes. No problems. I have towed lots more (very carefully).

I had a bolt on stage 3 for the LWB. It disappeared while I was living out of the country. It looked like it would install easily with a little angle grinder modification.

I had a Gen2 SWB (heavier) in Australia with the 4-bolt hitch. A professional car hauler said it was certified to 750kg (1650 lbs). He also said the SWB should not tow more regardless of hitch.

I have towed more with my '89, but very carefully.