Parquet laid continuously without joints

I would leave it. The warranty period is long. Put it in writing unilaterally in the form of an understanding email with indirect speech and that's that. Presumably, nothing will actually happen. If it is a local established company, you have little to fear; they won't destroy their reputation over a few joints. If it's the backyard floor layer from far away, trust less.

Definitely leave it as it is. This is common practice. Nothing will happen at all and it looks so much better! We intentionally did it like this as well, no problem after years. The adhesive is like rubber and simply accommodates small movements. The important thing is the edge gaps in the rooms. And 1 cm is more than enough!