Full slot not maxed out allows for very reliable up time..  Most of my gear will be  65 miles from my home.

I estimate I would make 20 visits a year to the farm if I stay riser free.

If I use rises for 50+ cards I will need to make 30 visits a year.

so 130miles round trip plus tolls any trip I can save is good.

I usually won't make the trip unless 10% of my gear is down.

I would love to make 8-12 trips a year  vs 20 or 30

Riser free will help.
Take a 8 slot board with 5 cards .  5 risers could be bad or 5 cards could be bad only 10 things can go wrong and since I don't pack the boards I have 3 spare slots.

Take a 5 card riser board.  that is 5 usb cables each has 3 points of failure the male end the female end and the wires in-between
there is a riser with a usb socket and a power socket that is 3 points of failure  and the riser can be bad so 4 points of failure.

lastly the adapter that joins the usb and the mobo jack has 2 ends so 3 points of failure. since something in the adapter pub can be bad so

3+4+5 = 12 spots that can go wrong vs 2.  so if you  do 5 cards to a board 60 spots that can be wrong.

the board you linked can run 12-13 cards so 12 x 13 = 156 bad spots.  lets say you under fill to 10 slots

you have 3 spare slots .  you still have 10 risers you need to trouble shoot .

Now if you are doing 1 rig in your house that's okay to do a riser setup just don't fill the boards.

Ie you want 26 cards don't do 2x 13 card boards  do the same 13 card board and use 8 + 9 + 9 = 26 cards.

and have a set of 6 extra risers.  that is not hard to manage since it is all in your garage.