Flex Back Strap adjustment

Some times I see Flex boots that have too tight adjustment with back strap. The tight back strap does not hold the boot any better on the foot than if the strap is adjusted firmly.
You should be able to add one finger under the strap when properly adjusted. Bulbs should have room to expand in every step.
This is a photo of our young horse. He is wearing Flex boots 24/7 now when it is slippery again. You can see that there is a space between the hair and the strap under the neoprene gaiter. Actually, the strap is little loose, but when the boot has a good fit, trim is good and made weekly, the boot stays on perfectly fine.
If the boot is slightly loose, FlexPad EVA or FlexPad KEVLAR offers extra protection to the sole, stimulation to the frog and sole and helps to keep the boot in place.

Above you can see two pictures with straps too tight. The holes of the straps are stretched, and it should not happen. 

Below you can see that the strap tightness is perfect, no stretching holes.
However, in these pictures there is 2 holes under neath the rivets. Ideal is to leave only one hole, or none. 

If there is more than one hole underneath the rivets, you can cut the strap to have only one hole or none. Picture below.