Cooking recipes are guidelines, baking recipes are rules.

I improvize a lot but even if I tried, it's never going to be the same. Vegetables differ, condiments can differ (if you open a new pack/ bottle) and I don't measure everything so the ratio of ingredients differ too.

I like variation. But if I'm looking forward to a specific recipe I'll want it the same as that's why I like it. I can still appreciate other versions of a dish, though.

First off, bolognese actually goes with tagliatelli in Italy. Spaghetti is used for other dishes so it's a little closer to real Italian food when you use tagliatelli.

I always see recipes as suggestions. I want to know the technique, outcome, and ingredients but after that I go completely off on my own. I will often read four or five recipes and then combine what I like out of all of them to make whatever I wish.

What always matters is - does it taste good? Sure. Sometimes if you vary so far from a recipe it's inappropriate to call it the same thing, which is fair. If someone tells me I'm getting a cheeseburger and they substitute the beef for a pork chop, I'll still be happy but it needs a different name.

Sometimes your own intuition of taste can make a dish much more desirable.
I do it with chili and other tomato dishes.

At one stage I researched Spaghetti Bolognese recipes. I found 3 that claimed to be the original.. I tried each exactly as their recipes prescribed. And the adapted the bits I liked in all three into my own.
One family member had discovered adding bacon to theirs and another adds crushed chilli to his. I have tried to add those too. It's fair to say the recipe is constantly evolving.
Who knows, you may end up making something entirely new.

I always try a new recipe as it's listed. I may vary ingredients next time to suit my tastes

I usually adapt the best I can if I don’t have a non-essential ingredient.

If you were working in a restaurant, the exact reproduction of a recipe would be crucial. Otherwise the restaurant owner couldn't call the dish Spaghetti Bolognese on the menu! Restaurant goers expect the dish to be exactly the same every time.

But home cooks like you, (and me), usually get creative, OR we just pinch hit and use whatever is in the fridge. It's a riff, if you will, on the original dish.

You can call it whatever you want, if it tastes good doesn’t matter to me.

I do that as well but can't call it spag bol if it doesn't have the spag in it! 🤣

It has to be exactly as stated in the recipe, or else the Dego Police come and arrest you for dishonoring Italy.

Truisms about this subject (and many others).....

"Variety is the spice of life"

Same old / same old....gets boring very quickly...

Then it’s a tag bol as you didn’t use spaghetti

It's it a general guidance rule imo

things like soup I definitely improvise a lot even just chucking in leftovers or whatever. but if I am baking a cake or something I try to be more exact.

Over the decades I tweaked my signature recipes to where I never deviate to where they developed and evolved, they would taste vastly different if I did.