Go a half inch over your length goal that way you can stop all together and recede down by a half inch, instead of having a cement or maintenance routine. Then just do your kegels when you can and jelq a few times a month to keep your penis healthy.
Are you going for more girth once length is done? Doing your girth work will be a cementing routine for length when done. I will not use the PF anymore once I get my length, it'll just be girth work and all day cock ring. I know I'll keep my length no problem. The expansion will make sure of that.