i haven't had any problem with Bell Ringer capsizing; but i make more than a half a SheepShank; by making 3-5 half hitches in Standing Part to grip bight of Bitters with. Also, i make sure that the loops that get tourqued into these Half Hitches are all alike/ same direction: either overhand or underhand loops. Then; finish with overhand knot in the Bitters bight. Easy to stretch out further for next load after releasing Overhand; must make the lacing further from truck to be able to compress shorter for subsequent loads, for easiest adjustability.
i favour riggings that allow unused line to be stored on vehichle by Bitters fininshing at or facing truck. Or, in the example of the prussik back to self for adjustable loop; that all line is used/ out of the way.
Only light loads pulled with bumper hitch; otherwise pull is from inline pull point on frame. Ball Hitch on bumper is generally a leveraged pull on bumper; not inline witht he frame; inviting failure/bending of bumper etc. i keep a carabiner in frame hole on my rear frame; on opposite side of exhaust for a quick place to hook too.
Never stand, sit, look etc. (unprotected) inline on a rope under such tensions as these. That line breaks, and it could cut ya in half! So, watching what you are doing, not letting load jam, being aware of what you are pulling; and thereby forces on line you are invoking is very good! Also, we generally throw some wood in back of turck at start of day and keep it there all day; or replace. This extra weight directly over drive axle gives much better traction. All ways back up at delivery point to take tension off line; but not so much as to run over line and challenge tiretrapping line against hitchpoint on truck. Pulleys on carabiners are nice placed on anchors, to pull load one direction, unclip carabiner/pulley and then continue pull; essentially giving a right turning path to spar/ load.
i used to have an olde lil'Toyota truck with hood all caved in. Could drag from rear and load hood up with firewood too. Then would pull and haul to destination; gun it in and then stop sharply. Wood on hood would self eject from the inertia; and wouldn't have to unload it! i only had to get out of truck on destination end if i had to untie load i was dragging; otherwise was a quick round trip and only getting in and out on one end to re-load!. i called it my inertia dump truck.
On the flip side; with a bigger truck or heavy equipment; several spars/ brush piles etc. can be pulled at once in train by use of half hitches on intermediary loads; extending to a half hitch on nose of final load with a later anchoring hitch on the final load in train. Many hitches (including Timber, Clove, Running Bowline etc.) are made to pull perpendicular to load/ spar; so that the Turns are inline with Standing Part. But dragging is an inline type pull on spar; that will try to pull on turns around the host spar perpendicular to the Standing Part; leveraging force agianst the Hitch. Preceding with a Half Hitch; hust grabs the host spar in the Half Hitch and the force flow continues on(the part after the Half Hitch is inline with the part before Half Hitch). This makes an inline pull that just grips the spar perpendicular to Standing Part; but the pull is inline; as the line continues to trace down spar. Then; it terminates at another grab point (Timber, Clove etc.); that leverages the forces as termination is perpendicular to Standing Part; but only after reducing the tension pull in the line so that it is not leveraged to more force than the initiating Standing Part pull; only leveraged by direction!
The placing apart of the 2 grab points/ hitchings in itself gives some inline pull dynamic; so the farther they are apart; in general the straighter the pull. Like in drawing 2 farther apart points; then connecting makes a straighter line. With just a Timber, Clove, Running Bowline to pull from on front of spar will even give more 'sway' as the hitch tries to pull perpendicular to spar (so hitch will be inline to itself); but because the forcepoint of the hitch pulling is spaced away from drag and Center of Gravity of spar; this wins out as being the more major factor of being inline; and spar drags fairly straight with some 'sway'. The inline pull strategy of preceding with Half Hitch reduces/ negates this sway. This is why the ABOK bible has 2 seperate chapters on spar pulls: Chapter 21- "Hitches to Spar and Rail(Right Angle of Pull)" and 22-"Hitches to Mast, Rigging and Cable(Lengthwise Pull)" back to back. Also, many lacings in chapter 21 are similair to those in 22; with a preceding Half Hitch type strategy employed.
Proceeding on to Chap. 23 "Hitches to Stake and Post, Pile and Bollard"; we see more of the right angle pulls of strategy. There ar no parts after the coils around host to place inline with the initiating Standing Part pull; and the back of the turns themsleves are inline with the Standing Part Pull. So we find that the inititating force is inline with it's equal and opposite on the backside of the spar; so is not leveraged against itself. When calculating these flows of force; we must look at each change/port seperately to define(as it is a seperate machine/ cog of the whole system); and keep defining until we reach the termination of the force flow in the Bitters.