I did about the same thing yesterday - gnawed through so much forest, two treeguards spawned (gnawed through them too). I ALMOST got lost, but somehow managed to find my way back before turning back into Woodie (I would have died since it was mid-winter). Then I spent about 2 or 3 days filling up my chests with all that wood!

I also spent some time chomping through boulders (since he can gnaw them too, funnily enough), so there was a crapload of gold and rocks to collect. Took me a while to figure out where they were once I turned back though...

By the time I transformed again (next full moon), I still had half a chest or more of wood, plus I'd barely used the gold and boulders. I guess the only thing to watch out for is to try and turn back into Woodie when he's near base, especially in winter...

I also love having him gnawing through pig heads and the occasional, annoyingly-placed merm house.
I haven't tried it yet, but I'm planning to make him sleep through the evening/night when Woodie would turn into a beaver if I don't plan to gnaw up any loot in his beaver form.

I tried the sleeping through the night trick - it doesn't work! I can't remember if you wake at night, or if you still skip to the next day, but I definitely remember using a tent and then turning into a beaver immediately!

Also note that a full moon lasts for two nights, so maybe that's why this happens? I've noticed that if I change back into Woodie after one night (due to full moon change), then I get the missing inventory bug. If I save and then reload, he immediately turns back into the werebeaver!

After now surviving about 2 winters, I'm starting to get really annoyed at his curse - I now realise why it's a curse! I haven't had to chop down a tree since the first change (sooooo much wood stored!), so now in werebeaver-mode it's a matter of just eating enough to last two nights of the full moon (so the bug - if that's what it is - doesn't occur), then waiting it out. I don't want to explore since I'll likely get lost (almost happened a few times!), then I'll be in the middle of nowhere with 50 health, 50 sanity, 50 hunger and no tools or anything...

I think it won't be long before I play as someone else. WX-78 for example is awesome after this update, and the fact that he doesn't care about spoiled food makes him easy to survive with, even if his starting stats are really low.

I guess it might indeed have to do something with the two full moon nights. Normally, if you spend the night in beaver form, then turn back during the day, the next full moon just passes you by, so you don't have the curse twice, but if you've slept through the first night, the second one will get you.
I wonder if he also turns into a beaver underground?

Also, I've found an interesting bug with this form: if you have the beaver gnaw something to fill his health JUST when he'd pass out, he'll keep the beaver form, but the music ends, and even at 0 HP (or better called log points?), he won't turn back. However, after saving and reloading, he's Woodie again - with full Health, Hunger and Sanity! :)

Actually, I'm pretty sure that whenever I turned back into Woodie after the first night (but before the second), I'd get the bug where you change back, but the inventory is still missing, and the log meter is still there instead of the other three meters! Then when I save and reload, it looks fixed for about a split second when BAM! He turns straight back into the werebeaver! After that I think it usually works OK.

Actually I'm not sure it's connected to the 2 full moons anymore, now that you mention that. Might just be randomness? All I know is that when I wait out 2 full days and nights, I don't get the bug. Could still be a fluke though, or maybe have to do with the time he changes back? I don't get the bug if it's daylight and 2 days have passed, that's all I know so far. They'll probably fix it soon enough anyway, but I'm going back to WX - that constant turning into a werebeaver was getting a bit annoying...

Yes, it is annoying, and that inventory bug doesn't help matters. (I'd have thought they fixed it with the unannounced hotfix released the day after the update...)
Right now, I'm playing with Wickerbottom, but I think I'll start a new game with Woodie again - I love a good log armor, and he can collect wood for that very quickly.