Sara,
Thank you very much. That is a very generous and kind offer. I don't mind helping people and companies who work so hard to improve their products and keep their customers happy. I'll PM you in a day or two with contact info.
Please wait as least a week for others who have more experience to comment and provide a sanity check on my advice about the vents before you make major design changes to your tents. I gave it a bit more thought and thought I should mention the 4 inch flex aluminum ducts we can purchase locally are actually 11cm outside diameter, the 6 inch ducts are 16.5cm OD. Make sure a cup with a 11.5cm diameter lip can pass through the sleeves if you don't want customers complaining that your "4 inch" ports are undersized.
I also assume a lot of people who want to convert to or add LED lighting probably already have 6 inch ducting and fans, etc, so making vents large enough for existing equipment may be in your best interest. I think if you need side vents in small tents at all, they need to be placed more out of the way, instead of positioned to cool a hot light. I think venting exhaust out the top is usually the most practical. Vents and ducts on the side just waste floor space unless they are in an aisle, above head level. I'd rather have 2 vents up top, in the corners. Hopefully a few more people will chime in about whether they think it's a good idea to downsize, move or omit the "HPS lamp vents" in your new tents.
Here's my grow tent with the door open. I built a base from scrap plywood on casters so I can easily move it around and get it out of the way while I don't need access to it.
Here's a pic of the door hanger and the corner reinforcements I like. The door hook originally came with a spring closure, but I cut it off so I could get it back off the D ring without a lot of difficulty. You should be able to hang and release the door hooks with one hand. They don't need to stay attached through a typhoon.
Here's how I attached the SCROG support - Pink nylon cable ties. - It can be adjusted up and down the pole and holds pretty well. No need to engineer fancy clamps, just drill a hole in the ends of your existing cross supports. The black stripe is some electrical tape I put around the vertical pole joint to keep out moisture and prevent separation.
Here's what my vent flap looks like after my modification. I cut the threads holding the flap to the tent. Then I moved the velcro on the flap bottom to the outside top edge and attached velcro to the top edge of the vent on the inside to act as the hinge. I put all the seams of the vent back together and glued a piece of wood along the bottom edge to stiffen the flap and hold it straight. Note the flecks of LED light making it all the way to the bottom through the thick canopy
A view from the back of the tent while the exhaust fan is running. It opens and closes about 3cm at the bottom. I have my fan turned down as far as possible (drawing 10 watts). My cheap 4 inch fan draws about 80 watts at full power and pushes far too much air for my small tent.
Here's what I would probably grow in a new tent; I started both clones and fem seeds from the Rocklock strain, and have rescue clones of BlueDream and Hindu Kush.
