So let me get this straight, and by no means do I want to step on any toes here, so forgive me if I do. Your saying it is better to flower with MH rather than HPS. Im no expert by no means but this goes against everything I have every been taught, seen or read. I kinda thought everyone knew to use MH for veg and HPS for flower. Maybe I have been researching the wrong information highway.
No. HPS is the bulb to use, IF your only using 1. If your using two or more, a "Blended spectrum" is preferable. MH lights encourage trichome production, along with low RH.
As for my opinion, I think I'm seeing airy buds. Your light might be too far away. Or the glass might be taking out too many lumens. Usually air coolers use 1,000W lights for this reason. Not discouraging you, just saying. For every foot away from your light source you go, the lumens level is cut into a quarter. So a 95,000L Digilux is 95,000 lumens 1 foot away from the bulb. At two feet that's only 24,000L. At 3 feet, 6,000L. I would not recommend putting a MH in a tube, because glass absorbs a lot of UV radiation. Also, nutrients might be a factor. Micro-nutrients are required for resin production. Make sure your nutrients list Copper, Boron, Manganese, Iron, Molybdenum, and Zinc. If organic, try General Organics seaweed. Great trace source. Try to control RH and temp. Air should make leaves "Dance" a little. Good luck and keep growin'.