Extra transactions will cause extra bloat. Fortunately, space is cheap, and the blockchain isn't growing that quickly, so it's unlikely to become unmanageable any time soon. If it truly did get too large(keep in mind that bitcoin's blockchain is only up to about 20GB, which although annoying to download, is hardly significant for current hard drives), there are some things that could be done to try to lower it. The current block data compresses very well, and just for the sake of testing, I ran it through winrar and was able to decrease the size by more than 40%. Obviously that isn't a format you'd try to run in-line, but I'm sure you'd get significant gains with something else that you could use to directly save and load compressed data. Another possibility is blockchain pruning could be attempted to be done, although that would likely be controversial, as it would break the ability to verify all the way back to the beginning.