Ah never mind, it clearly states in the description that no re-download will occur if already installed. I should have RTFM before asking. Thanks!

@blueprint Hmm, That is weird considering if you have the free game, the SC just gives you codes for your account. You may want to open a support just to verify.

@ERICK001BC I was able to buy the SC and the items were available automatically in game. No reinstall or re-download was needed.

@blueprint Nice, Glad it all worked out.