when i was tandem towing, my average load on the receiver hitch was 2500 lbs. up to 3k max a few times. my custom built receiver hitch for the rear of the old 5th wheel was bolted in so the frame could flex. i didn't want to weld it because of any tensile strength issues or lack of stress relieving activities, or breaking any welds. i did this for about two years. i now have a TH which i am thankful to the Good Lord for that blessing. but tandem towing never bothered me. got a lot of peculiar looks though. the whole rig measure 62'8" long. yeah, big train a coming!
so i think if you went with something on the rear, you'd be ok. just check clearances. i do like the nose carrier for 5th wheels though, that looked cool. i'll just put my bikes in the TH now.