No change to the shock is necessary. Even with the completely stock shock the improvements will be very noticeable.
We prefer the DPX2 shock on the Druid for the best all around performance with the link. If the rear suspension still feels harsh, we recommend working with a suspension tuning company to lighten up the compression and rebound tune on the rear shock to get the bike a more lively feel. This combination has proved to work great to provide a plush feel off the top of the travel while still providing plenty of bottom out resistance.
This link delivers substantially more bottom out resistance than the stock link. Using 30 to 35% sag should be your starting point. If you feel you need a little more first try adding a few clicks of damping to account for the change in leverage curve. If you still want even more you can try going up 10-20 psi in shock air pressure.
At 30% sag this link will also deliver much better small bump sensitivity so start there. If you still feel like you’d like a little more try running less damping. The link makes it so the suspension doesn’t rely on damping as much to avoid bottom outs so running less isn’t an issue.
The link doesn’t change the static geometry of the bike. The only geometry affected is wheel position at full bottom out.
Your best bet is to give Forbidden a call and ask them directly. Only they can make that call.