I’ve managed to beat every Proving Grounds with SEE as my only GL. Reliably? Not really. I did beat the Interceptor event, but only needed a few shards and so only needed a handful of successfull attempts. Never 3 starred it, haven’t 3 starred Ben, don’t think I 3 starred Malgus either but idk.
SEE also is by many measures the cheapest GL - he needs “only” 1700 Kyro pieces and 470 Flawed signal data. For a bit of perspective, Jabba needs 2900 Kyro pieces and 545 Flawed signal data, LV needs 3,300 Kyro pieces and 870 Flawed signal data, and even JKCK (whos reqs are only needed at G12 to qualify) needs 1600 Kyro pieces. And those are just gearing the reqs, not gearing characters needed for the reqs. SEE doesn’t need any major Journey Guide characters as reqs, with all being farmable besides EP and Thrawn who can be attained with a G8 Pheonix team. Other GLs need secondary Journey Guide farms like JKL (for JML/Jabba), GAS (LV), Wat (JMK), Raddus or Finalizer (Rey/SLKR).
I think he could use some changes, and I hope he gets a lifter before SLKR, but he has his uses and he’s a fast GL for those who need that.