i would run the light in the 12/12 cycle.
4.5 min on
10 min off
15a timer and dedicated outlet 15a breaker.
I believe it would have affect the bulb life but that does not matter
Whether it's important to you or not, Mr Moneybags
, you better
believe that it'd affect the lamp life! HPS lighting should not be hot started. Unless in a fan-forced cooltube, 10 mins is not enough time to cool the bottle & socket to ambient temp. It is startups, even from cold (but especially hot), that cause the most wear on an HPS bottle.
I could see a time-to-fail of just a few months (or less) using the cycle you propose and I don't see the benefit from winking the lamp on and off. When you remove the source of light energy being thrown at the plants, any additional growth you get from that light energy would stop as well.
A better solution to poor bud development down low on tall plants is to just not grow tall plants! This is what SoG is all about; tailoring the plant to the foliar penetration ability of the lighting.
By flowering clones immediately after they have developed a good spray of roots, with zero veg time afforded between setting root and flowering, you get short plants, finishing about 30-40" tall depending on the size of the light.
Any branching which develops on the lower 1/3 of the plant gets pruned off in wks 1 & 3 of flowering. The small lower branches will only develop small, fluffy buds which are a pain to manicure. The extraneous branching also blocks airflow around the plants, encouraging powdery mildew and other nonsense.
With SoG, you naturally get smaller plants, so you just grow more plants. Each SoG plant only needs a 6-8" circle. However, the method eliminates small 'popcorn' buds, increasing the avg bud weight & density by putting all the foliar mass within the best coverage area of your HPS lights.
Make the plant suit the light instead of the other way around.