I have had my dinner and a wonderful dinner it was too - my wife is a brilliant cook. She pours love into every meal and it shows in the outcome.
So, with that out of the way, The fundamental equations all have simplifying assumptions. Even the equations of GR and QM are based on simplifying assumptions. Otherwise, you wouldn't have various scientists disputing their veracity.
I have copies of a certain portion of some work done in the 1960's which look at the assumptions made for the development of QM. The particular author quite clearly demonstrates the various assumptions made in the development of QM. In his case, he removed some of those assumptions and redeveloped the various models. He came up with a different formulation. I have over the years tried to have a good look at the work in question to see if there is things that can be engineered from the work.
There is a certain level of mathematics that I am still trying to wrap my mind about. It is used in both models (QM and his). From my perspective, it does away with the strong force as unnecessary by making a modification to electromagnetic theory and it gives what you see in experimental results.
Does it have merit, I don't know. But I am happy to put it on the same footing as QM as a possible explanation of what we see.
There is a model that also does away with gravity as a separate force. The model in question formulates gravity as a residual effect of electromagnetic theory. Does it have merit. Again, I am putting it on a similar footing. My attempts to use a CAS have only been partially successful as I need to understand a bit more about Maxima first and what I can do with it.
For me, these are ongoing interests (among many) which I dabble in when I have time on my hands. I am looking at one paper that does an analysis of SR and as yet I have not finished studying this paper. The author's main conjecture is that SR only works because Einstein made some simplifying assumptions by which SR then gets the measured results. His conjecture is that if those assumptions are not made then SR gives the wrong results. Does it have merit, I can't say at this point. It again hinges on whether or not I can get the work into Maxima. For the same reasons above, I only look at this when I have time on my hands.
Many people assume that the E = mc2 is a specific formulation of Einstein's work. Yet in my engineering undergraduate days in the late 1970's, the same formula was developed directing from Classical Electromagnetic Theory with no recourse to anything that Einstein did. But even here, it is not a simple equation that is correct, you have to know what the E represents and what the m represents. It is context sensitive and you have to know what the assumptions are.