everyone needs at least an "internal" deadline so they are not in limbo forever. Your h does not need to know this if you don't want him to if you are worried that he'll see it as an ultimatum. Any ultimatums, IF ever given, better be followed so be careful with them.
But for me, I had a 2 year timeline b/c my older d was in high school and I could physically keep them in the same place/school for that amount of time and feel that some stability was there. Most people cannot do that. If you can, consider it but you have to know that you will be alright and that there is an end in sight. It's a very fair reasonable thing. Internally I felt that 2 years was pushing it a lot for ME, but it was a goal b/c of the girls.
Will your h know? And what will be different for you if the 6 months ends and you decide it's over? Will you file? Are they any signs he could show that would make you change your mind OTHER Than a complete reversal? Like the "gray" areas.
J-
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016