Drawing Fixatives: Recipes and How to Make them?

I’d like to start a discussion regarding fixatives and their various properties (also workable vs. final fix), sourcing them in liquid format (vs. spray can), and recipes for making them from scratch from quality raw materials. ​

I’d gotten into the habit of not fixing the majority of my drawings as I’d often return to them weeks, months, years, and occasionally decades down the road. Which isn’t to say I’ve never used spray fix (see addendum). 
Due to that I have thousands of drawings and sketches which have never had any fixative applied. The dominant medium is graphite and/or charcoal being the next populous (some small percentage might incoerporate some ink, pigmented felt tip pens like Pigma/Sakura, Prismacolor pencil, or perhaps a bit of gauche or watercolor). 
Being as three rattle cans of Lascuax Fixative will cost $100 and will only service a fraction of my drawings, it seems more economical and environmentally sound to purchase a large volume of fixative in liquid form, for ex. fluid quarts, half gallon, or gallon and use my own HVLP spray setup to apply it. (I have one liquid product sourced years ago – Reworkable Blue Label Fixative, see addendum). 
Even more economical would be to make my own fixative from scratch with the raw ingredients.
To that end a few questions:
1.) Are there standard recipes circulating for practitioners who prepare their own fixative from scratch? in NYC there’s art archival/conservation suppliers and/or chemical houses (Kremer, Talas, etc.). 
I’m not up to speed on the chemistry but if I understand correctly fixative is essentially a resin (Paraloid B-72 seems to be the standard?) dissolved in a solvent (or solvent blend) along with pressurized gases to suit the spray can format. What else is typically included in the recipe list? UV stabilizers? Matting agents? Other?
Some ingredients I see on MSDS: Xylene, Ethyl Acetate, Paraloid B-72, Methoxy-1-Methylenthyl Acetate.
2.) What’s the difference between workable fixative vs. final fixative … both in ingredients and performance? My understanding is that workable fix is intended to be erased and drawn over/into while final fix is typically functioning as a complete sealing coat of sorts. Is it just  matter of degree in the proportion of the resin that’s responsible for the distinction or is there other additives/omissions, etc.?
I don’t have a background in  chemistry, but I can follow directions measuring and mixing components and perhaps research whatever I’d need to learn in order to get all the materials optimally into solution and mixed in order to spray. 
I have access to high quality HVLP spray guns, large capacity compressor/regulators/filters, and exhaust ventilation so the spraying setup isn’t an obstacle. I imagine that a sophisticated spray gun setup would potentially result in a higher quality application of fixative vs. a rattle can’s  cheap plastic disposable nozzle as the former has the capacity to adjust pressure (which changes in a rattle can as the pressurized gasses are depleted), atomization, flow rate of material (to suit ambient conditions such as temperature & humidity, distance from work, coverage, etc.), the shape/size/pattern of the spray, along with direct feedback as to the volume of fixative in reserve. 
Any thoughts, comments, suggestions?

Thanks a bunch!

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Addendum:
I do have a few cans of spray fix I’ve accumulated over the years  as listed below (most are 10 or more years old). Anyone have any info/experience with them?:-Lascaux Fixativ #2070 (300ml)-Blair #105 ‘Very Low Odor’  workable matte fixative, 12oz, -Blair #01-10506 ‘Very Low Odor’ , 4.5oz. -Blair #105  ‘No Odor Workable Matte Fixative, 12oz [are we entering the realm of visionary marketing/magical thinking/consumer manipulation?]-Krylon Workable Fixatif #1306, 11oz.-Grumbacher TUFFILM Final Fixative, Matte 11.75oz-Reworkable Blue Label Fixatif (Martin/F. Weber Co.), liquid,  16 fl oz. (“use atomizer or airbrush to apply light application”).I’ve also used a few Senellier products sold in liquid form, plastic bottle with manual pump atomizer ( (i.e. not pressurized): ‘Delacroix’, ‘Latour’ (pastels), D’Artigny (oil pastels). This was some years ago.​