What happens if an improvement is not planned in the specifications?
Well, we are going to the grain: the specifications in a public tender is like the Instruction Manual to build an Ikea furniture, but with fewer drawings and more small print. There they tell you everything you can and cannot do, what pieces you need, how things should be seen ... Anyway, the rules of the game. Companies grab that document and, hopefully, do not sleep by reading it before presenting their proposal.
But what happens if a company becomes creative and wants to put an improvement that does not even appear in the sheet? Well here the thing gets interesting (or frustrating, depends on who looks at it).
First: it depends a lot on the law and the institution that is organizing the tender. There are sites where they are more square than a Rubik's cube and, if your improvement is not in the sheet, they simply ignore it. I mean, they don't appreciate the intention. Everything is evaluated based on the written criteria, so if your "great innovation" does not fit there, because they basically overlook it and you stay looking at the infinity.
Then, there is the least fun option: they reject the proposal to go outside the script. If your improvement collides directly with what the specifications say, forget it. The specifications have legal force, so if you leave the lane, they get you out of the game of one. No way.
Now, and this is where life becomes less boring, there are bidding processes where they value innovation and improvements. Places where, if you contribute something really useful and know how to sell it, you can take advantage. But be careful: you have to argue it well, demonstrate that your real improvement adds something, and it is not only to show off that you are the smartest in the room.
In short: Do you want to propose an improvement that does not come out in the specifications? First, talk to the contracting body or a legal advisor, do not perform crazy. Study the specifications well to not put the leg, and if you decide to do it, prepare to defend your idea and show that it is worth it. If you are lucky and the process is flexible, they even thank you. If not, well, at least you tried.