I’ve been cooking at home, and occasionally in restaurants, since I was about ten or so. So, 40ish years.

No single standard is better than the others. It does suck that there isn’t a single one that is used as a base, and then gets converted by the cook into their preferred units and structure, but even that has issues.

The good news is that most cooking, and even most baking, is very forgiving of the kind of discrepancies between sizes of lemons, onions, etc. You don’t really run into trouble until you’re dealing with things that react chemically based on the ratio of ingredients, which is still most common in baking, and not even all baking.

Even in those types of recipes, it’s usually flour that’s the problem, not leaveners, since flour compacts readily and to a high degree. But, then again, most modern recipes like that are going to be in weight measures, or in baker’s ratios. You’d be using a scale for the fiddly recipes.

So, generally, just guesstimate your produce size the first time you make something. It’s not going to be so far off that the results will suck if the dish itself doesn’t. Then you tweak things until it fits what you prefer, which is what happens anyway as you build your recipe book/collection.

My old recipe book had scribbled notes in the margins from years of refinements. When I copied that into a digital recipe manager, I added them in directly. Now, I’m able to just enter the original recipe, then add my notes as parentheticals or whatever as I refine.

Even with those detailed notes, a given recipe won’t always be reproducible as exactly the same. That’s because you just can’t standardize everything. You use good produce, there’s going to be varying water content, slight differences in flavor compounds, more or less sugars, so to get the same results over time, the cook has to know how to adjust for those things on the fly.

Of equal import is that no matter how scientific your process of recipe development is, the table is never the same as the cook. My taste buds and brain aren’t the same as my wife’s, my kid’s, my cousin’s, etc. So there’s limits to the benefits of standardized recipes on the plate.

Now, formatting? That’s a huge help.

You want your ingredient list to include instructions about when an ingredient is used in multiple places. You want lists broken down in sections when a recipe calls for multiple procedures (like making the main dish, a sauce, and a crust).

In the instructions, make sure the ingredient quantities are included for redundancy.

If there’s an instruction about duration that’s variable explain what the variables change. As in: bake for 10 to 15 minutes. Okay, great. What’s the difference? If my stove runs hot and I go for the short time, will I see golden brown, and will 15 be burnt or just really dark? Yeah, you can’t expect identical results from one circumstance to the next, but at least drop an “until golden brown” at the very minimum.

That applies to any variable, imo, but it can get to be too much detail in complicated recipe.

Cooking and baking are chemistry, physics. But they’re also an art. The more you try to strip a recipe of flexibility, the less successful it’s going to be for the next cook.