Advise you don't stick your torch in the freezer to get a little more fill space for safety sake. Probably best to have a little bit of air in there - 10 -20% - whatever a fill from a good can of butane gives you after purging. This is from the butane lighter thread here on FC some time ago (not VC jet thread, one of the other old torch lighter threads - think it was this
one but may be another). If you overfill with pressure beyond what the seals on these cheap lighters can hold, it could lead to all sorts of problems besides the simple ones like leaks and premature lighter death. And, if you're freezing to fit more butane then letting lighter sit at room temp or higher - you're overfilling/over pressurizing the tank!
Think most of us get comfortable with butane with so much use (maybe a little too comfortable?), but it is nothing you want to lose respect for. IMO it's just not worth it to fill that other 5 - 8% of the chamber. A leaky seal when lighting could lead to anything from an unexpected handful of flame to a full explosion. Unlikely, but why make things more dangerous and put more stress on your torch to top off a bit more when you're going to be refilling soon either way?
IME a good fill will give you the same flame on the same setting when properly filled. If you freeze first, you also usually have to turn it down for a bit at first, then adjust back up after you get to "normal" fill level. A good jet torch shouldn't need much adjustment once you have it where you want it. When it needs a filling flames will sputter or not light, and you may be able to adjust flames up to get a few more heats. But, I find it better to switch to another lighter at this point and refill the first one next time I'm back to my butane. Better to turn it all the way down for refill, then back to point it works best for you before lighting. Every lighter I have (10 or so?) does well with this method.
I picked up one of DVs 3x jet Vertigo lighters with last order. Really like it! Works like a champ on nearly every click, visible tank, easy fill with easy adjustment. Just wish there was a 2 jet available that was exactly the same. Haven't been able to find one anywhere. I prefer a 2 jet, but use these 3 jets on cap most of the time, or leave the 3rd one out in front so not quite heating. Wastes a bit of butane I'm sure (probably a bit less than 30% with front of tip getting a little heat), but works as well or better than any of my 2 jets.
IME some lighters need more burping/purging than others - as in both different models and different lighters of the same model. This one seems to be doing well so far without much. Others do better with a good clear of all air before every fill. Burp and fill as described above by others for best results. If you do this and are still having problems, working the lighter after it settles from refill (5 mins) can help work out issues. Just light repeatedly for a few seconds. Get it going well for 4 or 5 lights in a row. Let it cool for 5 minutes and repeat. 3 or 4 of these short sessions can make a big change - especially if you were using crappy butane. I think because you clear out every bit of residue from whatever problems are in the tank, and it burns off any light crud on the jets.
If burped, good butane, and still not doing well after working it like this - check for good spark from igniter. IME this is where you usually have failure that leaves the lighter unusable. Actually should check for this BEFORE refill of any that are being very problematic. Not hard to do in the dark. You should see a good blue spark with every click. If you don't - it's probably time to replace the lighter - or the ignitor if you're up for that sort of thing. IMO not worth the hassle for something so cheap. I just trash them when the ignitor dies.
If you have a good blue spark, clean the jets. I use a small brass brush (like a toothbrush). It doesn't take much, but you want to concentrate on the ends of the jets themselves and try to stay away from the little ignitor. They usually won't hold up to much abuse. I go dry with the brass brush working it a little back and forth in each direction, then little circles around each jet, then in and out to try to have bristles clean the actual little holes. Tamp on to a paper towel or something on a hard surface. Continue until you don't have any black bits (carbon) while tamping. Sometimes this will bring a nearly dead and very annoying one back to life. Sometimes not.
Funny, my experience has been exactly the opposite with Gen 4 Ti tips and my 6 month or so old OMNI. You're using stock VC body? Maybe DV adjusted the condenser length due to reports from me and others of this problem? I've been able to adjust my MP off the threads inside for no air - or use a Gen 3 or lower Ti tip for expected results. So, I'm good. Not sure how else besides what you're doing to get more air.
FWIW, I'd like to mention again that when I brought this up here in FC a while back, George himself sent me an IM offering to do whatever he could to make it right. I ended up with workarounds I found here and figured out, so am all good. But, how cool is it - and how about that customer service - for George to see my post and contact me personally? Fucking LOVE George and DV!!!!