Yes, leaving the skin on seemd to increase the acid level just a tad and also gave an off taste that did not exist in the other batches. for future reference I am always going to peel the mango's reguardless of type. It isn't all that bad if you use the edge of the knife to catch under a corner and pull inline with the direction of the skin. It comes right off, you can pit then peel or peel then pit it doesn't really matter.
I have also found that using a straining bag isn't a good idea either, just toss the mango's straight in and let all that gunk float around in there. Gives a much better and believe it or not cleaner taste for some reason. But you will need to stir the must daily, lovingly and it seems to help extract the flavor a LOT! Then just filter when transferring fomr primary to secondary and let the lees settle out for a month and rack again into another bulk secondary as you will do this a couple more times unless you use a clearing agent and sulfites. We use nothing at all in ours and tell everyone it is totally natural and will last about 6 months to a year from bottling date. Refirgerated it will last about two years.
I suppose everyone is shaking their heads at me for not using sulfites, well I will have some potassium metabusulfate in another month (mainly for sanitizing equipment) but really, if the wine is popular and you are careful why use it? I may drop some in one batch just to see how it comes out in storage a couple of years later at our high normal temp range average of 82 deg F.
Also, if you have a bruised mango feed it to the iguanas and the birds, forget throwing it into the must!!!!!!! I use a fish net suspended under the mango trees to catch the fruit. otherwise you have to pick it off the tree. Fallen mango's have several issues one of which is worms that get in there almost immediately (and some you my not even see they are so small). Yes they are a lot of work but if it was easy everyone would do it....
Mark