Wellgo 98R might be worth a try, it's hard to find definitive info on interchangeability with SH70/SH71 but at least they are cheap and current production.
This bloke says SH-5x cleats work fine on PD-7410 and PD-6500 and he has obviously tried it more recently than I have. If I remember to take my MTB shoes next time I have the Hirame out, I'll have another go, I could be misremembering the reason why I have so many pairs of shoes with different cleats.
Wellgo seem really similar indeed, and they appear to be out of stock in many website so I assume they are not in production any more! Better hurry up and stash a few pairs then!
Exustar E-C04 is another SPD+pontoons cleat. The trouble with all these Taiwanese OEM companies is that they have very hit-and-miss retail distribution.
Wellgo 98R might be worth a try, it's hard to find definitive info on interchangeability with SH70/SH71 but at least they are cheap and current production.
This bloke says SH-5x cleats work fine on PD-7410 and PD-6500 and he has obviously tried it more recently than I have. If I remember to take my MTB shoes next time I have the Hirame out, I'll have another go, I could be misremembering the reason why I have so many pairs of shoes with different cleats.