It's definitely not "technically" correct, but it can work in a pinch. On the flip, it can also be one of those things that works out in lighter sparring but gets you brutalized in a fight.
A good bit of something to always practice while slipping is to make sure you're slip is out and in. Pop that head back to the center at the same speed as the slip so it can be moved again. If you get lazy and "hang your head out" where you just slipped, you're asking to get hit with the 2.
Firing or angling off at the very first moment you realize that you've slipped to the wrong side can also help. A sneaky flick jab works from there, just don't stick around.
Against a tall, powerful, 1-2 fighter it's definitely dangerous to slip inside. That what 1-2 fighters are looking for. Deontay Wilder, Lennox Lewis, or those twins from Chicago are all guys who use the front foot as a yard stick and focus on keeping you lined up. They protect the outside angle, win the jab game, and keep the back hand loaded. They try to use left side superiority to leverage you into the right hand.
But what about Tyson for example (for whatever reason he's always the exception I bring up).
He was basically designed to fight tall 1-2 fighters and he loved the inside slip.
Also why is it dangerous? i mean I know theoretically but still.
If you slip a jab to the outside then your head is still in line from a right hand, it's further away but still in line, I mean it's not where you slip to to avoid a right straight.
The path is longer so you have more time to react but you either need to block it which can if it doesnt work out perfectly throw you off balance or the right hand can still sneak behind your glove behind your head.
So the safest option from there is to either bob/duck the right hand or pull back, use your feet if you are quick enough and find another move to avoid it.
If you pull your head back from the inside slip, isn't that the worst thing you can do? You are basically perfectly in line for a follow up straight and your head is right back in the middle?
But if you slip to the inside why not just like tyson slip even further and/or bob down/change level with it and you basically avoid a 1-2 with one move.
Obviously it can be predictable if thats all you do and Tyson sometimes got caught with uppercuts when changing levels or still with straights or overhands but still it worked often?
I'm sure there's a reason why not to but I don't know it.