A read out from a timing machine will let you know how it runs in all 6 positions. You can then see how it compares with what you experience while wearing the watch (do you wear it every day, all day?)
Maybe you can find a position to lay your watch down at night that will compensate for the -2 sec/day that you are observing.
If that does not work, you can have your watch adjusted by VC's watchmaker, it is a very easy adjustment for a watchmaker to make the watch run slightly faster.
While some people may think -2 sec/day is not a big deal, it is your watch and what other people think does not matter. The good thing is you do not mind if your watch runs slightly fast per day. If you wanted to experience exactly 0 sec/day while on your wrist, that would be a much more time consuming challenge.
By the way, we NEED pictures of your OS Chronograph!
Welcome to THL and Best Regards, Dan