You've had no success trying to enlarge Animals by Magic, nor trying to speed their Growth. Unless you count "feed them often, regularly, plentifully, and nutritiously," which certainly seems to serve well in the natural way. You haven't attempted any test that seems likely to be destructive on your Connected creatures. That said, you have made some attempts at destructive testing - a few mundane spiders, a hungry coyote, and a single Bee (that was dying and specifically indicated it was fine dying faster for your Research) have all… basically exploded, and had their bodies turn weirdly Tree-like on some level. Non-Destructive careful testing has had no meaningful results. On the upside, you are fairly certain you understand why: you are Trees; Animals are different enough from you that you would have to find a workaround for the sheer differences, and the fact that Magic generally has no way to pull the correct pattern for a Squirrel from a Tree. You could spend a lot of time analyzing them, try to figure out how to get Magic to acquire their pattern from them via your Connection, or possibly even try teaching your Connected animals how to perform Magic. You suspect that all of those are possible, none of those are easy (the middle one perhaps the least difficult), and each of those has its own upsides and downsides.