Binding forearm to average of rigify limb bones

Does anyone have a rigify rig with the following features:

1 bone per limb part.
IK,FK with snapping

I am finding it hard to use the rigify with static limb portions. These are the following problems:

#1 Each of the 2 bones per limb part (2 per forearm, 2 per upper_arm) are at the far ends of the average value of rotation and scale of the alignment of the total limb. Eg they are at an extreme value of the actul alignment of the limb part. For this reason, it is quite necessary to presumably have a very fine gradient in the weight paint to achieve a smooth transition.

#2 I am intending to pose a fairly rigid body with deforming occuring at the joint, making the above outlined more distinct.

Am I missing something about the workflow required for the above? Let us presume that automatic weight painting does not achieve the objectives for a rigid limb.

#3 Perhaps, it is possible to deform to the average of these 2 parts or some other meta limb. Is it a reasonably expected workflow to deform to the ORG limb part?

#4 What do the following delimiters mean: ORG,DEF,MCH,smth?

If there is documentation for these delimiters I would love to see it. It would appear that with Automatic Weights only generates vertex group for bones that start with DEF so perhaps there is a contextual functionality to these delimiters.

ORG_PREFIX = “ORG-” # Prefix of original bones.
MCH_PREFIX = “MCH-” # Prefix of mechanism bones.
DEF_PREFIX = “DEF-” # Prefix of deformation bones.
WGT_PREFIX = “WGT-” # Prefix for widget objects

I am presuming Blender auto weight paints only to bones that have Deform enabled.

I use another bone, segmented to rotate under the control of the wrist, elbow or knee (not needed for shins in my experience). No paired bones on the limb parts, just one for upper, one for lower arm for instance. By anchoring a segmented b-bone that can only rotate in the Y direction (along its own axis) at the wrist to the elbow, it creates a smooth deformation for twisting, which is the problem you’re trying to address if I understand you correctly.

But then I build my own rig rather than use Rigify, I’ve never used it, so it might be different with that or something.

1 bone per limb part.
IK,FK with snapping

just uncheck "complex arm rig " in the rigify types “biped.arm”

#3 Perhaps, it is possible to deform to the average of these 2 parts or some other meta limb

1.1. just add a cop rot constraints to the DEF-forearm.01.L/R (influence 50%, both local space,check only y rotation) with target DEF-forearm.02.L/R and check “preserve volume” in the amature if you use the rigify type “biped.arm”

1.2. if you use the “pitchipoy.limbs.super_limb” in the rigify type choose many bone part you want. Its deformed in the average by default ( because the DEF-bones are conected) dont forget to use b-bones.

Is it a reasonably expected workflow to deform to the ORG limb part?

Never ever touch a ORG-bone these bones are only for generating the rig, its the glue between metarig and DEF/MCH- bones.