Glue emulsion

​I was a student of Patrick Betadier back in the 1990s and where I learned his oil-emulsion technique. I even have paintings that I did with him while a student. It is an interesting technique and painting practice. However, as a art materials specialist, I would not use the emulsion recipe because of natural resin content—dammar. Using dammar in oil paint layer makes the painting susceptible to solvents that may be used during varnishing and cleaning. Here is an article that provides more information on the topic:
Should Oil Painters Use Resin-Based Mediums such as Dammar and Maroger?

Sorry, I missed this and only noticed it when George responded. I do not know this specific technique, but I see problems at the outset. First, I would hesitate to call this a glue emulsion. In painting technique glue usually refers to collagen glue derived from animal skins/bones. Methyl cellulose is derived from cellulose which is a poly saccharide and not a protein.
Interlayering oil paints with lean emulsions can be really problematic, even they do not contain soft tree resins like dammar. What you describe reminds me of the technique used by Henry Ossawa Tanner in his later works, although his did include animal glue. He would layer emulsions containing natural resin, mucilage from flax seeds, parchment glue, and a tiny touch of oil between layers of traditional oil paint. Oil would certainly stick to these emulsion layers, but the problem is exacerbated when they were then applied over oil paint. There are just too many issues with adhesion and more brittle layers over more flexible ones. Many of Tanner’s later works on canvas are in very deteriorated conditions. Those on panels faired better, as one would guess.
Again, I am not familiar with the precise technique that you mention and am only responding to the general idea of interlayering very dissimilar media.

​There was a “gum emulsion” recipe included in Utrecht Linens’ literature ca. 1960 which seems like a similar concept, with likely the same drawbacks already mentioned. The author was probably one of the company founders, informed by study under Taubes and Mayer. (I am posting here as a historical footnote, not as a recommendation to use this medium) 
GUM TEMPERA EMULSION RECIPE
Gum Arabic Solution, 5 parts
Stand Oil, 1/2 part,
Damar Varnish, 5 Ib. Cut, 1 part
Thoroughly mix the gum arabic solution with the damar varnish and stand oil solution with an egg beater. The Micro-Sperse color is then mixed with equal parts of gum tempera emulsion and kept in tightly sealed jars for months. The egg, egg oil and gum tempera are thinned with water.

Certainly, a resin that dries insoluble (and long-oil alkyd binders are essentially a synthetic and less yellowing version of the old hard-resin in oil binder, like hard copal varnishes) would be preferable to having a readily soluble, soft resin in the paint.
I have not experimented with alkyd used for this purpose, but it sounds interesting. Even if this turns out to be a wonderful medium, I would only suggest it being used below oil layers and not above or within. There was a ton of work done in the 1st third of the 20th century using similar emulsions over, within, and alternating between oil layers and most have not faired very well.  The successful examples that I have seen were on panel and where the additions of emulsion into oil was very sporadic and non-continuous.
Mayer suggests these precautions in his sections on “mixed technique,” although that was written when it was generally accepted that such mixed media was far more common than is currently believed. Honestly, most researchers into painting technique now believe that there was little to almost no use of complex mixtures like those suggested by Doerner, other writers of the early-mid 20th century, and even the National Gallery, London just a few decades ago.