Fur buyers aren't tanneries.
And as I mentioned, commercial tanneries and home tanning are two very different things. Commercial tanneries are working with huge vats, where a small amount of borax won't affect anything. Those large vats are also constantly monitored for the proper pH. That same skin thrown in a 5 gallon bucket pickle will cause problems.

I only use salt when tanning-no salt or anything else is needed to dry fur.
People use borax or salt to try to shortcut the drying process,or to make up for deficiencys in handling

"Salt absorbs water moisture because it is an ionic compound with strong attractive forces for the highly polar water molecules. This property means that salt is hygroscopic, meaning that it absorbs both liquid water and water vapor in the air."

Using salt slows down the drying process. Not much of a short cut.

I use boards. And I don't skip the flip.
I tan many furs at home. When I started tanning I had ear slip until I learned how to taxi flip an ear.
I also lost some fox tails because I skinned and froze them without splitting the tail.
As I've said before, tan some of your fur and you will find your weakness in your put up.

Its a shortcut-a foot not properly skinned out will rot.before it dries.Takes time to properly trim a foot(or ears or head).
A foot not properly skinned out and heavily salted wont rot.
Its used as a shortcut.

Using Borax for cleaning is a lot different than using it for tanning. Those using it this way will usually never see any problem with their fur using a processional tanner. They use such careful measurements on the PH and can control it so quickly that most fur is saved, unless heavily saturated.

Doing paws like Boco has mentioned means opening up the paw and working them to the nail, a tedious process for the unlearned, and seemingly time consuming as well, but for presentation in taxidermy and especially for Mountain Man crafting
it's a must for top dollar sells for material to those who cannot or are unable to harvest their own pelts.

I'm not saying one cannot sale pelts with the paws not turned but they will get more dollars when you do as the paws can be re moistened and spread out nicely, it makes a more dramatic affect in presentation of a Cape hat

I generally won't even buy full turned pelts if the ears are not cleaned or the paws are not turned unless I have done purchases with a harvester before hand and I am comfortable with their work.

Long as I know I'm taking short cuts when I sprinkle a little insurance (borax) around my turned ears and properly skinned out feet.

"Split the leg
down to the main pad then carefully skin out the rest. Allow about
one day drying and then turn out and fill it with borax or sawdust
until its dry"

FHA pelt handling manual.

How much fur bought from FHA will be tanned in a 5 gallon bucket in somebody's basement? I think you and Boco are maybe discussing two different things. For sending fur to FHA I don't see a problem with borax as it will be commercially tanned, but for home tanning I see that may be an issue

Salt doesn't slow the drying process, it speeds it up by pulling the moisture out of the skin. Hang a salted hide next to an unsalted hide and see which dries faster and more completely.

That is true in low humidity-However-a dry salted skin that is hard as a rock can turn back into a floppy skin if the ambient air has high humidity.
The salt will draw moisture from the air.
Salted skins held for a long time can deterirate due to a salt loving bacteria-the Halophilic bacteria.You will notice it on a salted skin as pink patches.that grow over time.

Absolutely, I just don't want people to think that salt will slow down drying. It will make drying go much faster, and honestly I think most people trying to how to tan at home should salt dry their skins. The more that can be done to reduce bacteria the better.

I will salt fresh skins I am going to tan for a couple days rolled up.I dont want them to dry.I dont like salt drying however it can be beneficial in some cases.
If I want to tan a fresh beaver in warmer weather when I cant frostscrape to thin them down,I will salt dry them and dryscrape them.Dryscraping is more difficult and trickier than frostscraping..If you thin the leather with a currier knife or skinning knife a good time to do it is after they have been salted for a couple of days rolled up(not dry)Before washing degreasing and pickleing.
Salt dried skins are prone to damage .If they are folded hard they will crack.
Another thing about salt.Salt is used quite a bit in the tanning process in different steps along the way.Tanned skins must have all the salt removed from them before finishing.
One of the problems with some home tanned leather or furskins is "damp" leather in humid weather..This is due to chemicals-especially salts that have been left in the skin while tanning.
If you store home tanned fur in a basement in summer check the leather to see if it has a damp or slightly clammy feel to it.if it does this is due to the hygroscopic properties of salts left in the leather.This will shorten the lifespan of a tanned skin by quite a bit.

Tanned skins need to be grease free also to prevent premature deterioration of the leather..

No need for that if you know what you are doing.
better to have a greenhorn try to save one than having it rot.
Do it right-split the webs and flesh off the padfat with poultry shears.

If I ever have my feet come back bald from a tannery from using borax , I'll let you know. I don't send taxidermy skins to FHA to give away. That's for greenhorns.

PM me your addy and I’ll send you a replacement fox to tinker with.

Man I appreciate your kindness but I can’t take advantage of your furs like that!

lol Trust me, it’s not a big deal.

Delivered.

Delivered indeed!!! Thanks again