Depends on what you mean by "latest". R6RS is arguably huge. That's why they decided to split R7RS in two, a small core which is done and a huge version which, ironically, is still in the making.

R7RS is still in the making, not because it is bigger, rather due to politics that many don't agree with it ever happening.

The small core exists, because that was the only subset their were willing to agree on.

right, it may not happen, but at least some people want to add stuff to scheme that will make it larger, to eventually reach the point where it no longer can be called a small language.

i don't know if/when that point will be reached. my comment was hinting at the potential for scheme to become larger.