Rendering panoramic movie with isolated animated models

Hi - I am using the movie capture plugin to capture a 360 panoramic image of my scene (this works fine).
I have some animated props in my scene that are hidden for the panoramic image capture…I want to enable their visibility and render these animated props as stand alone animated .png sequences [so that they can be layered on top of the panoramic scene in after effects].

What is the best way of 1. Rendering only the items that are selected, 2. Ensuring that they have an alpha channel and 3. ensuring that they render with the same camera angle as the one used in the 360 panoramic render ? I have been trying with the sp.force alpha, and ‘setting actor hidden in game’ to everything but the animated props…this is exporting a png with black background (no alpha) and also seems like an expensive method of exporting as I am rendering a 4k image for the sake of a prop that is 120px x 120px.
Any advice ?