Boost chaining, if you will, count toward the ones that proc damage increase off X amount of hits. Tag switching or “Your partner launches” type of stuff is also good. I personally things with the condition of “your partner launches” for hit confirming into launchers so that my incoming characters have something decent. So for example something like my current team Sagat and Law. If I see a bad whiff, I’ll punish with s.HK~HP+HK (can’t mash boost HK~HK~HK), Law comes in, c.HP~somersault juggle, c.HP~dragon stance into knuckle, then dragon kicks for pretty hefty damage. If I wanted to carry them further into the wall I could do c.HP~spin kicks with Law and switch Sagat back in. There are some gems that will activate off tag switching. I haven’t used them a whole lot myself. There’s a lot of experimentation still needed.
IMO the best ones are the ones you can absolutely activate whenever you want. The “your partner launchers” gems are a good example of that. This also works well with the meter version where you just bring in your character and tag switch a bit more and build back the meters used up in the process very effectively. Sethlolol runs a lot of those gems on Law for meter building and you saw it fumble in the match against Infiltration since he wasn’t able to hit him much. But on the other matches where he did get to touch people he was able to confirm into some good tag switches.
Most of the free gems are listed here: Gem Synergy & Optimization (NO ASSIST GEMS)
Someone on SRK compiled the gems here too: http://robofobe.com/sfxtgems/
Raw tags are 100 damage initially. Tatsu did a beautiful reactionary raw tag on Infiltration using Rolento’s command roll, there’s more things vulnerable like that here that’s a WIP: Low Crush Research
Some of the bigger combos I’ve seen involve a locking down type of attack while switching someone in to charge up EX or Super. Ryan Hunter did some nifty stuff on this guy in a replay I saw. He catches the victim with Steve’s command grab gatling punch thing toward the corner, switches Julia in and does 2-3 neutral jump HK, then juggles with Julia and finishes the BNB for like 500 damage. With that he basically rebuilt the meter spent switching Julia in and may have made even more so he could have switched Steve back in also after maybe a DP ender with Julia from the initial switch.
There’s just way too many fun and awesome things in SFxT being plagued by boost chaining and silly looking timeouts being shown on stream.
Here’s Big Boss/Yung_Ice with some DLC meter gem in action with Law/Lei combo tag switch, charge up Super and then a Level 3 Tag super. It’s like a 70-75% damage combo with about 3 meters. The gem procs almost a full meter I believe, but I didn’t look into what specific condition was required. He spends 6 meters here. Tag switch (1), charge up super (2), and cross art (3)