1) Does not provide any ASET/Hearts & Arrow image
- It really depends whether their supplier provides them or not. Not all diamonds that are rated as Hearts & Arrows by suppliers are actually as good as those you can see at those vendors such as WhiteFlash or JannPaul.

2) The diamond should be with supplier, not under them, that means it is under Virtual Inventory, to put in more layman terms, it is like pre-order thingy, you want, then they order for you. If you wish to view some diamonds, try to ask if they have any actual diamonds that meet your criteria on-hand.

3) I don't think there is any vendor that can guarantee you that in Malaysia, if you are deeply concerned about this, I would suggest you to visit brick-and-mortar stores that actually provides the real diamonds. You can try to visit JannPaul in Singapore, I have people telling me that their custom cut outperform their usual Hearts & Arrows round brilliant (the standard round).

Yes, this diamond has nice proportions, it should perform well. And yes, you are right about the arrows, so it won't be 100% Hearts & Arrows.

My advice is, try to set a balance between price, cut quality, and expectations. Good thing is, the light performance thingy ZCOVA is using, is actually quite a reputable name in the industry (SARINE). I think even Diamond and Platinum is using it now: https://en.prnasia.com/releases/apac/diamon...ei-292022.shtml, and that is for their Estrella collection (their signature).

So, if you are curious, try to visit Diamond and Platinum to have a look. I think from there, you can roughly gauge what kind of proportions you like personally, since Diamond & Platinum has real stocks on hand.