BoyBand|KamiBuckets

Not a JRPG, but Card-En-Ciel combines a JRPG combat vibe with the feeling of Yugioh at its wildest engine-wise (e.g., Metaphys, Zoo, Fire King, Exodia draw, etc.). It's a bit goonerish in presentation, but eh, it's gameplay heavy. SMT VV if you want to have exploration on par with ER, along with the ability to buildcraft to take on open world bosses at big level gaps. Devil Survivor if you really want your time respected. No exploration in the sense of walking around, but you play through 7 days with various events being available, including side quests and secret bosses. If you play well, you only need to interact with major content, and it has enough routes and potential builds to run through multiple times. And, Soul Hackers 2 on Very Hard (free DLC to unlock the difficulty). The dungeons aren't great besides the Soul Matrix mazes, and story depends on how into anime you are. However, on Very Hard, SH2 is probably the most challenging while fair (no cheap deaths or stat checks) JRPG to date. I was avoiding emulation (though Devil Survivor can't go unmentioned), but Radiant Historia is great too. It's a spiritual successor to Chrono Trigger in ways. Time travel is core to the narrative/progression, and it has a very tactical battle system that wouldn't be served by words, but it'd be very quick to start it up and know why if you can emulate.