question on moving CG to rear most position on Phoenix..

original install CG was more forward , I am in process of moving it rearward some each flight , no BIG changes as i am moving it slowly to rear setting so far.

question is ?? ... will it get alot more unstable flying in a big jump as i near the rear most CG setting ?? ,,, or will their keep being gradual changes closer i get to rear CG setting ?

just do not want to reach critical stability and not be able to land while changing CG to rear.

where is CG for others flying Phoenix ?

thanks, Joe