Well, in earlier versions of wasm I was able to create vectors of payments that included egld and esdttokens as well. Isn't that possible anymore and if so why not?

Just pointing out what dorin said :) I myself find it useful :) Also you should be able to create a custom struct/enum to store it in an efficient way and that also implements ManagedVecItem :)

There is no reason to have a ManagedVec of EgldOrEsdt, since there is no API function that allows you to use it for anything. You'd ultimately have to resort to manually searching for an EGLD instance in the vec, which is not what you want to do