As benitto said, decoys are incredibly broken even though they're probably the best recon gadget. DGMK is broken, it's not nerfed, 15m is 100% useless, it's broken.
"Aimpunch" is a good thing. In older titles this was a part of regular suppression, and it was the counter to snipers having dominance at range. Even if you can't really kill them, you can make it way more difficult for them to land hits. At least in older titles, now in BF6 you pretty much just don't challenge a sniper at all ever or you abuse CoD movement mechanics to avoid fire. Bad change, bring back real suppression.
All the nerfs benitto offers to make sniping more difficult I completely agree with. It's a sniper fest out here, and snipers are one of the reasons the larger maps in BF6 just feel terrible to play. Increase barrel inertia however, because it's stupid that a dude with a 10x scope can just do acrobatics while still holding perfect aim. Flail that scope around just like would happen in real life too, I'd like to meet the man who can hold dead center walking across uneven terrain with a 10x scope. Most people wouldn't be able to do it with a 2x scope.
Flare for DMR that kills with two bullets... what? The 8.6? The SVDM? The 8.6 sucks, but the SVDM is pretty good. Dunno what this means.
Claymore damage is fine, if anything increase the range that it can be triggered. Sick of people running past it because it has a 1m range.
Other ideas
Forward recon need more forward oriented gadgets. The DGMK used to fit this role until it was broken, along with claymores, but that's not really any option at all. The decoys are ok at close, but not great. Their native gadget the sensor seems designed to be a forward gadget, but since the sniper is usually far back it's practically worthless. C4 is super niche, and great when it's great and just takes up a spot when you don't. Technically, this is fine, because it's the risk/reward trade in effect here that we don't see enough of in this game.
Again, the passives need a rework, just as any other class. As with my post for assault, I can only really remember a scant few passives, and for snipers I know they get ohko headshots and can spot gadgets within a certain range. That's 4 other passives that I can't even name because they're so pointless. Again, remove the unlock procedure to get them, and just make them an always on passive.
If sweet spots are going to exist, then so do overly large and obvious lens flares. If the sweet spot can be removed, then I'd say the flare should be toned down AND removed for anything under 5x or so. Forward sniping with the SV and no scope is actually a lot of fun but it's insanely restricted because of the scope options, IE none if you don't want a "shoot me now!" flare every time you look at someone.
I also recommend severely lowering the flare with the designator. That thing is just a giant red target every time you even think about using it, and it's more of a detriment because the entire planet can see that thing and immediately start firing everything they have at it.
Most DMRs need ROF buffs, and recoil increased. The point of a DMR should be that it has viability at range but can still at least hold it's own at close. Currently they feel like sub-par sniper rifles because they just can't keep up, minus GRT and LMR. People really sleep on the LMR too, but it also needs an ammo capacity buff. Every other DMR sucks against real snipers, and sucks against regular full auto weapons.
All in all
Fix the dummies. Man I hate how broken they are.