By Template, I assume you mean what the new caption workflow calls "Caption Track Style." The style applies to all elements in the track and the position is in the style. So as soon as you apply either style, it changes all the captions to that position.
See my post here providing some additional information about Caption Blocks. Note that you can "style" the blocks differently (e.g. position as you say), BUT if you apply a Caption Track Style it will affect ALL Blocks in the track. Meaning they will all move the whatever position is set in the style.
https://community.adobe.com/t5/premiere-pro-discussions/captions-showing-2-caption-tracks-at-the-same-time-2021-workflow/m-p/11912151#M336322
Regarding adding an additional Caption Track, you can only have one active at a time. You can embed multiple closed caption tracks in a video, but you can ONLY burn in one track.
Stan