Is it a cause for exclusion to use a format other than required?

Yes, look, if you skip the format that they ask you in a public tender, you are basically digging your own grave. That is, the rules are not there to decorate. The roll of public tenders is super legalistic and, believe me, do not walk around: if they say that the file has to be PDF with lyrics Times New Roman 12 and double space, because you better give it to you like this and not in comic sans in a .docx, because they send you directly to the dead file.

That whole thing in the format is not only because they are obsessive of order (which they are, but well), but because they need to compare proposals without walking where each thing begins or ends. Imagine the chaos if everyone sends what you want: one in Excel, another on recycled paper, the other in hieroglyphs ... it would be impossible to check it.

Besides, following the format demonstrates that you have two fingers in front and you know how to obey instructions, which in these processes is worth gold. Not that you are the genius of the lamp, but at least you know how to read, right?

If you spend the format for the arch of triumph, they can get you out of the process without blinking. Sometimes it is automatic, other times the entity can turn a blind eye if you like it or if the error is not serious, but in general you do not risk, because there are people waiting for you to go down the leg to stay with your place.

And be careful, it doesn't matter if your proposal is the best in the world. If you didn't follow the format, Bye Bye. It's like getting to a wedding in Pajama: even if you are the soul of the party, they take you away.

My advice: Read everything with magnifying glass, follow the instructions as is, and if you have any questions, ask before delivering anything. Better seem intense than being out for nonsense. Thus, at least, if you lose, it will not be due to a primary error.