I know it’s not what anyone that ask this question wants to hear, but You can carry a spare on it as is, because the spare sits very close to the bumper and is a fixed attachment…
But I would forget the platform or bike rack that would be extended beyond the spare… Then weight of the heavier bumper and supporting iron will eat heavily into the rear load capacity of the trailer… None of the chassis parts not just the bumper are built for it and you may also void the warranty on your new trailer by modifying or welding on the chassis…
This is the very thing that brought about the TH designs… others that claim to have done it successfully or not, would not equate to being a good idea… especially with some of the questionable set-ups that get recommended on the forums here from time to time…
In the end, it’s your trailer, your nickel, and your liability if it fails and I have seen plenty of those…
Good luck and above all be informed before diciding…
Love my mass produced, entry level, built by Lazy American Workers, Hornet