Yes. eSIMAdvice currently lists 10 Ohayu Australia plans.
The lowest displayed Ohayu Australia plan is Australia · 3 GB · 15 days · 5G, at $6.74.
Australia · 50 GB · 30 days · 5G is the current best-value match by displayed price per GB: $1.12/GB ($56.24 in total).
Yes. Eligible displayed prices already include the active ESIMADVICE coupon where the provider rule applies.