>Is the Sadsak slinky an exercise worth trying? <
It’s a good girth exercise but be sure you know what you are doing.
Plumped bends are maybe less of a problem but you need to do them with extreme care and stop bending as soon as you feel the tension raise.
With both of those make sure you don’t have any kind of erection and consider putting them off until you know exactly the limits your penis can take.
If I were you I’d work in some Horse440’s. The danger with this exercise is blowing a vein, so make sure you do them in a good light and monitor heavily. Again starting carefully is good with this one.
Its probably worth continuing your jelqing and throwing in a Uli and/or a Horse every few minutes. When you do that and go back to jelqing it seems more effective.
One thing I always found gave a good girth boost was a modified Sadsak Head exercise. Basically an overhand OK at the base of a 60-80% erect penis, release the grip a few times and kegel in more blood. Then wrap the middle finger around the shaft too, then the ring finger, and then the pinky. Hold for maybe 30 seconds. Repeat a few times at the end of your session. Once you have all the fingers of the hand involved in the grip it creates a good amount of force but doesn’t seem to be as aggressive on the outer veins as a Horse440.
Two months in your dick should be pretty well conditioned but ease into any of these things. There’s nothing worse than an injury from a new exercise or pushing one a little too far.