New Phanteks Evolv ATX case arrived, lovely quality but 2 of the Motherboard mounting posts are diff

Very pleased withthe case beautiful build quality, with solid 3mm thick side panels and top. Fabulous engineering for the price.
I think for £119 its really 12/10 value wise. The additional screws are very poor quality though, but the actual case is stunning quality, its as though someone put in the wrong acessory box, ?

I did notice that 2 of the 9 pre-installed Motherboard mounting posts looked different ?? Instead of a 6mm hexagonal post with a square end , these 2 have a sort of shoulder , admittedly they do have a spare 6mm long one, in the nice compartmentalised plasic box with all the screws.

These 2 different ones are both in the middle position, one on the top row of 3. And the other differently shaped one, again in the middle - but in the middle row. All the 3 bottom row ones are the same squared ended type and are 6mm high.

As these 2 looked longer, I measured them - and they are 7.05mm high i.e. Just over a mm longer and not squared off but seem to have a sort of sloping "shoulder"?

Is it normal on an ATX case that 2 mounting points are longer?
For a novice it seemed weird - as I have assumed the back of the mother board would be flat.?? So one would want the mouNting posts all to be the same height to make sure the MB is not bent as one screws in the secuRing 3mm screws.

I can't check the MB yet, as it is due to arrive on Wednesday with all the other stuff.

Any ideas? Should I be getting some replacement mountiing posts from Phantek?

BTW the Asus Hyper PCIe to M.2 pcie card arrived today - looks very well made, great quality.

The center standoff is almost always a "guide", meaning that you don't have to screw it in, it'll just protrude through the motherboard so that when you are placing the board into the case, you don't have to fiddle with alignment.
It seems that Phanteks decided to set two guides so that both alignment and rotation are set for you while screwing it in, and the spare post is for the top row in case you want to secure the board a little better. Maybe if you're going to be using one of those big 1kg air coolers like the D15 or R1 Ultimate.

can't picture the problem from the description sorry...

Thanks
Got 2 normal ones from Overclockers, and bought 2x 30mm stainless grub screws . Used them as a guide and then removed them and replaced with normal motherboard screws.

So sorted thanks for input.