It should be fine. Hammers tend to stress well and for the future, theyre fine on plugs. With growth, you'll never know the plugs were there and they have no impact on growth. This coral species isn’t terribly picky when it comes to the proper placement in your tank whether on plugs or not. The trick would really be just to avoid the extremes. Avoid extremely bright locations or areas of very high current, and avoid areas that are too dark or with currents that are too low. Remember that fast currents risk damaging the soft, fleshy polyps (and getting an infection). Bright lights will cause bleaching. Insufficient lighting will cause the poor coral to wither away and starve to death.
Hammer corals only require a moderate amount of light for photosynthesis and can grow well in the intermediate regions of your tank. Just about any reef LED lighting should be sufficient for most tanks. Reduce white light intensity and get it off the sand bed which sand can irritate it. The polyps should sway in the current, but not sustain so much pressure they are constantly bent over their skeleton. Too much flow will tear the polyps (worst case) and cause the polyps do not extend in the first place (best case). So, don’t give them too much flow.
