I have to agree with Victor and SirPickles. The high frequency in benching has helped me out tremendously. Bench press has also been one of my better lifts but still in the past 14 months I've put over 35 lbs on my bench max doing the Sheiko programs. The high frequency but rarely ever going to failure has worked wonders for me and many people that I've put on the Sheiko programs.
Here are some things that have helped me to keep the shoulders healthy with the high frequency of benching as well as things I've found to work get my bench stronger while on Sheiko
-Always keeping the elbows in tight and acting like bending the bar in half on the descent.
-Doing band pull aparts for scap retraction 2-3 x 20 reps each bench session
-Adding in some extra pull ups or rows on the Tuesday off day
-Doing light flys on double bench day (really opening up the chest and getting a good stretch and blood flow)
-Doing heavier DB paused assistance on single bench press session days when it calls for "chest muscles"
Eg- DB Paused Floor Press, DB Paused Flat Bench, DB Paused Incline, etc.
-Limiting heavier overhead pressing. I know some people swear by going super heavy on a frequent basis on overhead presses to help their bench but I've found I do better with a lower frequency (medium intensity) on these. (Normally Sheiko will have you do these only about 3-4 times within a 12 week cycle)