The only issue could be if you take Sputnik now and Sputnik V2 too soon, if they use the same viral vector in the future (you could develop antibodies to the ad

The only issue could be if you take Sputnik now and Sputnik V2 too soon, if they use the same viral vector in the future (you could develop antibodies to the adenovirus itself, afik Sputnik uses 2 adenoviruses for dose 1 and dose 2 for this exact reason) if the vector is different, they will both work(in the case of mRNA the vector is not an issue, afik). So if you're allowed to get another vaccine in a couple of months, take Sputnik now.