Would not be possible with Just another long and short position (DCA) to achieve that long and short position have the same entry price? so the negative PNL would be O?
Do you really think that this has not been tested or that the gap between those isn't big enough to make you lose money? I mean I have seen so many people who just want to use longs and shorts together to assume that they could make a break even at the worst case, when in reality if it was that simple to do it, then everyone would do it. Plus it also makes you never earn as well, not only you would lose, but you would never make a profit too.
In the end, do not try to find shortcuts or loopholes, just trade like everyone else and try to make sure that you are doing a good job at it. I get that it may not feel great for you, but the thing is that we are going to make a profit one way or another and won't have an issue.