meanwhile back on topic
I'm adding updates to the equipment sections - then will tackle the "Why" sections preceeding them
here's the latest.
Back Plate
The back plate and harness forms the foundation of the DIR diving system .
[36] . The back plate is used to anchor the harness, buoyancy compensator, and provides storage for other items. The back plate is a rigid plate with minimal padding
[37] bent from flat stainless steel
[38] or aluminum
[39] plate and slotted for straps, or formed from other materials with similar rigidity characteristics
[40]. The choice of materials is determined by the operational needs of the diver and the environment. The back plate is adaptable for double tanks and singles tanks as required, using either an adapter
[41] or strap cutouts
[42].
Harness
The harness is formed with one continuous length of 2 nylon webbing secured through dedicated top and bottom slots in the back plate
[43] [44] . The harness should not contain any quick release mechanisms
[44].
[45]The webbing must be adjustable and is secured with a single stainless steel buckle located on the divers right waist
[46], this position lessens the potential of accidental opening by the crotch strap
[44]. A crotch strap runs from the bottom of the back plate to a loop in front in which the waist strap is passed through, securing the harness/back plate system to the diver. The crotch strap prevents the harness system from shifting and riding high on the diver. The harness supports 5 D rings, one placed on the divers left waist, one on each shoulder strap, and two on the crotch strap
[44]. The left side waist D ring is used to attach the back gas SPG, stage bottles, and other gear that may be required for a particular dive.
[47]The shoulder D rings are used for securing the backup lights, the primary regulator when not in use, and temporary storage of other pieces of equipment.
[48] The crotch strap D rings allow for the front to be used solely for attachment to a DPV (scooter), and the rear D ring is used for attaching equipment as needed
[44]. The primary light battery canister is placed on the waist belt on the right, secured with a secondary stainless steel buckle or the primary stainless steel belt buckle as appropriate .
[45]
.....this is a tedious process since i am citing sources throughout to eliminate personal opinions from polluting the article.