Hello once again Carlos!
Mold is a very weird beast. You can live your entire life without ever having problems with it, and then all of a sudden it blows! I'm a physicist and not a microbiologist so I simply report my direct experience, that contradicts some points of what is common belief. It is correct to say that humidity is a mold promoter, but it is not correct that in-house humidity is normally below 50%, and also I would not say that high temperatures are needed. On the contrary, the three times that I had serious problems with mold the climate was moderate to cold: spring in two cases and fall in the other. I also believe that other unpredictable factors contribute to mold growth, like for example winds blowing a huge quantity of spores coming from somewhere. I say this because the same climate conditions described above happened other times, but fortunately I didn't notice mold anywhere.
This said, I'm not surprised at all that you have records treated in many ways all of which show no problems with mold. I also never had problems with mold until I had, and please note that in the past I have lived in a basement flat for almost ten years. In those years I even tended to believe that all this talking about mold etc. was all fuss. Then, as said, one day mold knocked at my door.

Observing what happened in those days, I think that some facts about mold became very clear in their striking evidence:
1) whichever object is not perfectly *clean* is prone to be attacked by mold: a fingerprint is more than sufficient for mold growth;
2) all fat compounds are an ideal substrate for mold growth: food stains, red oil for furniture, shoes and leather grease, waxes of various kinds (more on this later);
3) some supports, if "greased", are exceptionally prone to develop and promote mold growth: greased leather (belts, shoes, etc), oiled wood and oiled paper, clothes not recently cleaned;
4) chemical reactions driven by molds are very complex and are not restricted to the substrate, but have the power to attack the support as well: leather and paper can be sometimes cleaned perfectly after a mold attack, but other times they are permanently stained in various colours (from red to blue); metals like aluminium are deeply corroded and can no longer be polished, and so on. The same, unfortunately, can happen with shellack: record grooves are deterioretad with visible smudges and audible noises;
5) the more an object is "groovy" or "unpolished", the more easily it will grow up mold: fabric, cardboard, wallpaper, paint on the walls, record grooves (!) and so on. Also unthinkable objects like magnetic tape reels can be attacked by molds.
This said, the worst combination of all has proven to be grease over leather (an almost ideal "biosphere" for molds!) followed by greased wood and greased paper (= old 78 RPMs albums!). The more you steer off from those combinations, the safer you are.
Concerning wax specifically: wax tends to be more inert than grease which in turn tends to be more inert than oil. Also, the more the wax is refined and pure, the more it tends to be inert. For this reason, I would definitely avoid beeswax (which is rarely pure and can contain hundreds of other compounds, from sugars to proteins and so on) but also carnauba wax and stearin which are acid fats (shellack is an alkali) and are rarely available with sufficient purity, the first as it is a food additive (foods have a very low grade of purity) and the second as it is used in very low-tech applications such as stearic candles.
Again, we may question about pure paraffin or other synthetic compounds. Perhaps in the short term and extreme conditions yes: it may indeed have a protective (waterproofing) effect, should an item be stored in a very moist ambient for some time. But I don't really know in the long run and I wouldn't bet a penny. In any case, should it be applied to a record that, still, has to be listened to, it obviously has to be applied in a very thin layer that would be very difficult to be kept clean by other greases like fingerprints; also, being so thin, perhaps the layer would be easily saponified. I don't have a final word on this. Personally, shall I lubrify a record, I would use the purest paraffin available only. But on the other hand I can't really figure any reason why I should really do that.
PS: I get your point, but believe me: you don't really want to have experienced the big heat of this summer!
