I Support self-inserting....As long as it's done RIGHT!
I saw a few "Anti-Self insert" stamps and i was gonna comment, but, most of them had their comments disabled or i just didn't even bother with it cause i know it'll get me nowhere if i commented -_-'
I personally have zero problem with self inserting. However, i don't like it when the cannon characters are taken out of character so much that it's just a completely different personality.
I don't mind making the cannon character's slightly out of character, as long as it's done right tho. It HAS to make sense of what your doing. And i think that's why it's gotten such a bad rep these days to self insert.
We all know what happened with PrincessElizabeth013, AkaiDaliha, and some other people like them. The made their characters always too perfect, flawless, and even have god-like powers such as immortality, making people fall in love with them, hardly ever being beaten in a battle. basically, a marry-sue/garry-stue character that's un-enjoyable, bland and boring.
However, if you self-insert, and actually make your self-insert EXACTLY LIKE YOU (with an added bonus of a power that you'd like that's NOT OP. or if you want an OP character, make them have flaws in other ways. Such as limitations to spells/power abilities, or how long they can use that said power. etc etc.) Then the character will be WAY more interesting to others. Especially in the Sonic community. There's been so many bad marry-sue/Garry-stue self-inserts that it's just so bad that whoever makes a self-insert character, the people automatically will attack the user.
So, if you can somehow make your self-insert plausible, then no problem! Self-insert! Besides, as long as it's done properly, it's not doing anybody any harm whatsoever c: