This would be more likely to be answered in the DIY
e-liquid forum, but I just happened across it anyway.
TPA has some flavors that are very strong, and this is one of them.
Personally, I don't like M-Type at much more than 1 drop per 10ml (around 0.3%.) I've seen others report 1-2%, but letting it steep for at least 3-4 weeks. They said that it undergoes a great change for the better after steeping that long. I've never been able to let anything steep that long, so I wouldn't be able to verify that.
Last time I used that, I think I went with 1 drop of M-Type, 3 drops of TPA Bavarian Cream, and 7 drops of Ethyl Maltol 10% solution, did a hot bath and vigorous shake, and vaped it soon after. Both of those other flavors work well to round out sharper flavors, but I'm not sure if that would help with an over-flavored batch.
I'd probably use that batch as a sort of 'flavoring', and make a new batch using 20% of that, making it around 1% M-Type.