When you can get them incl. a siutable T12 fixture there is nothing wrong with them. They are much stronger like reptile bulbs so 1-3h per day should be enough but they are for sure more expensive and each time you replace them you have to pay additional shipping costs and custom fees. And shipping such bulbs is expensive because of the huge packages.
For EU peeps I recommend to get the Arcadia reptile bulb called D3desert(12%) or D3dragon(14%). They are strong enough to get the same results, you can use them for up to 12h as soon as the plants are used to it and they do not damage the plants no matter how long they are running. Plants need only a week to get used to UVB which means the 1st week only 1-3h but then there is no limit.
The Solacure bulbs are so strong they can damage the plants and they need a certain minimum distance of 20-24".
Reptile bulbs can be used with less distance. 8-12" with the 12% bulbs and 12-16" with the 14% bulbs. To cover 2x 2c area evenly you need at least 12" distance and a metallic reflector.
Why do you believe UVB light destroys your gorilla tent? I've seen many peeps using UVB and till now no one mentioned such things. Has it white coated tent walls? In this case its possible that you see a purplish tint with the time but with mylar on the walls there is no such coloration.
I've 325w white, 10w far-red and I add 20w hyperred this month so 355w LED and I have two 2ft bulbs now which means ~48w UVA/B. Works for me and means a 7:1 ratio. But only 12% is UVB and 30% of the 48w are UVA. The rest is visible light and should be added to the amount of LED light. Too complicated for my taste and even then its probably more UVB like the natural 1-3% of the sun light. But god thanks thats not an issue with reptile bulbs. I've used them 12" above the tops for 12" and you get ~150μW/cm² in the center out of a 12% bulb. So 150x 12h= 1800μW/cm² x 0,036= a wooping dose of 64,8kJ/m² directly under the bulbs. Calculated with 40% to come near to average numbers thats still 26kJ/m².
And yes, I've done w/ and w/o tests and have seen several differences.
I've used a well known GreenPoison clone for this tests and have grown the strain for around a year before I've startet to use UVB light. So it was pretty easy to spot differences because I knew what she could do.
The first differences you'll see is the plants grow a little more compact and stay shorter. Maybe because of the extra blue but this is also an effect of UVB. When plants receive UVB the UVR8 molecules gets destroyed and the plants recognize, "OMG, there is UVB! I need to protect myself and my possible babies as fast as I can".
Branches will faster get strong and woody, leaves stay a little smaller too, they also look darker because of more densely packed chlorophyll inside the leaves. The transition goes faster too and I've seen the first preflowers on the UVB side within 3 fecken days, you get less stretch and shorter internodial spacings too and last but not least the plants start earlier to from the 1st trichomes. Up to a week earlier! They do everything a little faster and and later in flower you'll see much more purple, red and other colors. I also believe it has a shortening effect on the flowering cycle but I've also used far-red so I can not say that for sure.
Positive side effect, insects and fungal infects are also no problem anymore. Insects can see UV light and they avoid it because it damages their dna and UVB kills spores pretty fast too. Not as fast as UVC does, this takes only seconds, but UVB is used for hours so you can be sure it will do the same.
I've also tested it with a usually slightly purple Bubba's Gift I've used a few times before under my 160w LED and with 24w UVB (12% Arcadia bulb) this strain ended up looking almost like a black widow. The upper half of the buds were almost black and the colors also dissapeared pretty slow with the curing. The buds are still visible darker.
Also the upper leaves ended up getting almost black and when two leaves have overlapped the lower leaf still stays green. So it was for sure an effect of the UV light.