How is the isolation on the KZ ES4s? They seem like they'd be ideal for the bus where I wanna keep the volume low and don't care too much about sound quality + a price under $25ish. The sound signature seems to be more mid-forward from what I've read compared to other KZ buds which is a nice bonus. I have the ZSNs which aren't very good at isolation with any tip I've tried and the ZS4s which isolate perfectly but are extremely uncomfortable to wear. The shape of the ES4s seems a bit smaller than the ZSNs so I'm hopeful that it will isolate better but without the discomfort of the ZS4s. Also had the EDR1s but those obviously aren't made for much isolation beyond the basic. I'll consider other options as well of course.