So I can only confirm the whole thing.
About 3 weeks ago, we also had an appointment with a prefabricated house manufacturer. At first, everything was still good, the consultant seemed nice and friendly.
At our first appointment, he explained to us what the general cost breakdown looks like and asked us about our wishes. Afterwards, he showed us a house that might suit us and wanted to prepare a detailed floor plan by our next appointment with a house that would fit on the plot we had reserved. But even during the first conversation, he asked us if we could imagine signing a contract next time. Of course, we immediately declined this and were initially a bit confused and found it strange.
A week later, he came to our home and showed us his elaborations (we found the elaboration quite simple, as he hardly changed anything). Well, after some time during which he told us a few more things, he finally showed us the price for the house and after a while, he presented a second price which we would get if we decided within one week. We found this very unpleasant because we felt all the time that he just wanted our signature.
We definitely decided that we do not want to build a house with this provider because we simply had a really bad feeling about it.
Two weeks later, we had an appointment with another provider and it was completely different there. Much more attention was paid to our wishes and there was never any talk of a contract. We were simply told to call when we had decided. After that, we felt much better about the company.
Anyway, I can only recommend to anyone to sign anything only if they have decided to build with that company and to have the contracts checked by a professional.