"Tripping pretty well" on 300-450 micrograms of DOC is well-nigh impossible. If what you have is really DOC, then the amount of material on the blotters must be significantly higher. Also, since you didn't use buccal or oral ROA, but rather a combination, it's not possible to broadly deduce if you have DOC, a lysergamide or an NBOMe (or related) compound on your hands. For example, NBOMe's are technically bio-available via oral ROA, but they are far more bio-available via buccal ROA. Meanwhile, DOC and lysergamides are usually swallowed (i.e. there's no need to leave the substance in your gums).
We will never be able to identify the substance that you have (and trying to do so is against forum rules anyway), but if you had chosen either buccal or oral, then we could have had a general idea of what's up. Lastly, the reason why I mention all of this is because if what you have is in fact an NBOMe, then you could get into serious trouble, especially since you don't know the amount of material that those tabs contain. For your safety, I suggest that you toss them and look for a more reliable source.