Basically I would like you to add a Ice Box (Basically an Ice Fueled Chest) that would preserve food allowing you to have the rotten food option on but still be able to stockpile food, also a config option to designate storage containers (items & blocks) as being refrigerated (like the Ice Box/Cooler Chest). It would make it possible to have interesting HC survival modpacks.
In addition would be nice to have compat with Serene Seasons/TAN so that cold biomes/seasons (essentially any place/time where snow could fall) essentially function as refrigerated storage areas.
Edit: Can't believe I didn't think of this earlier facepalm an item you could craft with blocks (let's call it a refrigeration unit for now) to make them refrigerated, you could even make it so that items crafted together with the RU would require RF/Ice depending on which version you use (both could exist at the same time, the RF version being more expensive) and make it into a refrigerated storage unit. That would make it so that you could set which blocks/items can be refrigerated.

I have some ideas about this: ice chest is probably coming possibly even with mechanical power support (apparently there's mechanical fridges, go figure). This can happen relatively early (Saw probably). Maybe something can be setup with HCBuckets and ice so it doesn't melt into full water blocks so ice farms are a possibility... Saw silktouching ice blocks? Not sure.

For food mass storage I will probably have lye production and the lye would sync up the rot of all items and also increase the time it takes to rot. This can probably be stoked fire tier.

Canning with bottles is something I thought about, I was gonna have it be "pressure-preserved" food (Dragon's Dogma gave me that idea with the airtight bottle). This should probably halt rot completely at the cost of being uncookable/uncraftable with and be relatively endgame.

However I'd like to reuse machines from BWM or create machines with purposes other than just preserving foods for this purpose, and until I come up with something good it's kind of hanging in the air.

You reminded me about this, LOL
Your ideas are better by the way :P
Edit: facepalm didn't even bother checking whether the link worked, so I edited so that it does, basically a rubber band powered fridge is demonstrated in the video.

A guy on the curseforge website had the idea of using minetweaker to create recipes for preservatives or canning jars, that's a good idea for early game food preservation.
reference link: https://minecraft.curseforge.com/projects/better-with-addons?comment=63
I would expand upon it by making the earliest be jerky/dried food which would decay very slowly, but not be very tasty (fills saturation a lot, but hunger very little), preservatives would be an item that would slow the decay of food (salted food would do the same thing if you have mods that do that sort of thing, speaking of which, you could have a config option for preservatives).
A Canning Machine used with bottles, preservatives, and your desired food would allow you to preserve food long term without refrigeration but would be resource expensive long term thus necessitating the acquisition of a refrigerated storage item/block for mid-late game storage.

• The Jerking/Dried Food & Preservatives Systems would be Early Game.
• The Canning System would be Early-Mid Game.
• The Refrigeration System would be Mid-Late Game.
• Adding compatibility to Cooking for Blockheads would be interesting recipe-wise but not necessary.

Apparently saltpeter was used to make ice a long time ago in real life, so maybe you could use the Niter from HCGunpowder in Better with Mods as Ice making and cooling ingredients. Heres some links: Link 1, Link 2, Link 3, Link 4, possibly more to come.
Edit: Link 2 has a couple of insightful links at the bottom.