I have found moving up from 28kg to 32kg as a working bell to be a significant adjustment. Here are a few things that have helped me get comfortable with the 32, building volume and extending the set length. The caveat is that I haven't tried any 5-minute tests [Edit: With 32kg. I've done the 100 rep cert test many times and 200 in 10 minutes with 24kg] and am not really training for one, so I don't have any direct experience with carry over to that format.
Q&D 044:
I really like the Q&D 044 format because doing two sets in a row on the same hand with shorter rest and then having a longer rest gives a nice balance of density and recovery, and it's very adaptable to a range of sets lengths (although I only use the two set format, not the four set format), and the two sets on the same hand helps with snatch-specific grip development.
I was using 28kg as my 10/2 bell and started building that out to 15/2, adding a rep or two at a time. When you get to 15/2, the going gets very tough (for hands, hips, and lungs) because the longer sets eat into your recovery time, so you are doing 30 reps on the same hand in around a minute and a half.
I started using 32kg for 5/2 and started building that out to 10/2 a rep or two at a time. 5/2 is pretty relaxed because the shorter sets give you more recovery time. I got comfortable with 5/2 very quickly and then started building on that.
Q&D 015:
I also started doing 015 sessions with 32kg, a set of 10 on the 3:00 x 10 sets, switching hands every set. It makes for a nice relaxed way to get in a moderate volume, with slightly longer sets than "classic" A+A. When I was doing classic A+A with sets of 5, I'd typically start at 30 repeats and wave up to over 60 repeats (this was with 28kg). But with 32kg and sets of 10, 10 sets feels like plenty. I find that sets of 10 are a sweet spot. If I'm only doing sets of 5, I find it's easy to muscle through it and be sloppy with my grip. With sets of 10 my technique has to be better and more consistent, and the longer sets build more grip endurance. Of course sets of 10 require more grip endurance in the first place. But I mean I find that practicing sets of 10 builds a comfort level and margin for error that shorter sets don't.
Things that have NOT really helped:
Using a "deep" grip:
tl;dr: I'm generally not a proponent of the deep grip except for very limited applications. After extensive experimentation with the deep grip, I've mostly abandoned it. It increases low rep grip strength, but at the cost of forearm pump, fatigue and reduced grip endurance that is counterproductive for most of my programming.
Longer version:
I had always used the hook grip (always = 20+ years) because it keeps stress off the callus line at the base of the fingers and is generally easier on the skin. It also allows you to keep the forearm more relaxed since it's more of support-type grip than a crush-type grip.
When I saw some heavy hard style snatchers mention using a deep grip, I started experimenting with it, and it did take some trial and error over time to be able to finesse it so I wasn't painfully pinching folds along the callus line. With the deep grip, there's a degree of goose-necking that's necessary to keep the handle from pinching the callus line and to keep the handle pulling more against the palm of the hand. Otherwise, the "deep grip" ends up being more like overgripping a hook grip, with the stress right at the base of the fingers. Some goose-necking lets you get deeper than that, into the palm
I did find it more secure for heavy bells that are at or above my limit for hook gripping.
However, I also find that the deep grip leads to much more and faster forearm pump. This isn't necessarily a problem with protocols like A+A, where I'm doing 5 or fewer reps per set, resting generously, and alternating arms each set. The sets are short enough so that the forearm pump doesn't build up too much, and there's time for it to dissipate between sets on the same arm.
When I first got the hang of the deep grip, I thought it was great and started to use it for everything. But I quickly discovered that while it helped with grip security, it was counterproductive for grip endurance. The hook grip allows me to keep the forearm much more relaxed and I find it much less fatiguing. As long as my hook grip is strong enough to hold onto the bell, I can stay more relaxed through a longer set and recover faster between sets. I'm sure GS athletes discovered this long ago and that's why GS technique has evolved in the direction it has.
So now I've reverted to the hook grip unless the bell is so heavy that I really need the extra security of the deep grip. And as I get comfortable with a given bell, the more I can transition to a hook grip with it.
For continuous snatching, or programming with more than 5 reps/set, shorter rests between sets, or consecutive sets on the same hand, I use the hook grip. When I started using 32kg for Q&D, starting with a 5/2 rep scheme, I was using the deep grip, but now I've transitioned to the hook grip for that and really all my regular snatch training (and I'm now up to 10/2 w/32kg using the hook grip). If you're dong something like Q&D or King-Sized Killer, or training for a snatch test, I don't think the deep grip is the best way to go. If and when I start using 36kg as a working bell I'll probably begin with a deep grip, but I'm now looking at it as a transitional strategy.
Heavy swings:
I've just never gotten much carryover from swing grip to snatch grip. I have gotten carry over from lots of A+A double cleans to snatches, but more from a hip power standpoint than grip. In fact, I've found that heavy double cleans make a great complement to snatch training because they overload the ballistic hinge compared to a single snatch, but are less taxing on the grip. So you can do them without frying your grip for snatches or when your grip is a little fried from snatches.
