You have the typical lack of throw to 4 low following a lift, that's fixable with a 13 mm wrench. Check into it while you wait for the cable to come. It isn't the flex but the twisting of the body and frame that is making the change...which means you are pretty far out of the proper throw range. The proper setting is 4 low with the handle about 3/8" from it's max "up" position....the rest rakes care of itself. I like Tri Flo or any similar plastic safe Teflon lube that has cleaning properties. Not dry lubes, but those that wash it and leave a clean film.
Also , in defense of the linkage...it moves ...what moving mechanical part the is exposed doesn't need periodic cleaning and maintenance.
Things get crusty and destroy themselves.
Most linkage threads would never happen if people would stop and consider that lever is connected to something...it's not "wireless"...several somethings actually...all chained together.
Also the Savvy really needs a lube port for a spray straw ... eventually they will get dry. Motion pro motorcycle cables had these at one time.
The feel and function of the Savvy is a true upgrade, you can shift to 4 hi or Low with a 2 fingers...but the linkage has survived for decades...despite the prevalent lack of maintenance they seem to get.
At the minimum, anyone that wheels needs to understand them enough to deal with them on the trail even if they have the cable.... to help out the other guy and make it home.