1st post with new handle (security purposes).... Although tin foil is not optimal, unless of course you want to prevent the reptilians from reading your mind. My best guess for the "problem" with your buds is that they have been flowered for 7 weeks under very low intensity light. Plants respond and adapt to the conditions you provide. Flowering with the UFO probably kept your temps down nicely, but the leaves that grew during this time are acclimated to low temps and low intensity light. The buds are obviously adapted to low light conditions. Now you've put in 400W of HID in place of about 90W of LED! I don't think adding an HPS 2/3 - 3/4 of the way through flowering is a good idea. These plants are never going to reach their full potential regardless of how long you let them sit under the 400W HPS. These plants were told how big to get weeks ago. I don't think they are going to change their minds at this point.
Plenty of us veg under low intensity lights, usually flouros. The smart ones veg for 5 - 10 days under "bloom wattage" or HID just before switching to 12/12. There is nothing "wrong" with your buds per se, but next time if you don't veg for last 5 days of veg under your HPS; at least bloom under it the whole time. You will notice a marked difference in the buds at the same flowering time. I'm sorry you were lied to about the current effectiveness of LEDs for flowering. I think we can all see that they just aren't there yet. For blooming HPS is the standard right now.
Heck I kinda wish you would put the UFO back up, let them finish (if they will), and post a tongue in cheek pictures of your LED harvest. Of course I'd be starting / planning/ researching for your next grow which will put this one to shame I promise you. There is a wealth of knowledge on this forum. Use it........peace PDC