New PC + NVME SSD with over 1TB Total Host Writes in less than a week, should I be concerned?

For me seems absolutely normal. Even at this rate (first week is likely to have some extra writes, due to software installation and updates) the 600TBW your drive is rated for should last for arround 600TBW / 1TB/week=600 weeks (12 years)

Since you probably wont use the computer so heavily as this week as I said (at least not installing that much software), and the manufacturers tend to be quite conservative with the TBW value (I still have an intel X-25M G2 from 2008, which was mounted in several PCs, and has 85% of lifespan), I would just ignore it and be happy about your new build.

There are some changes that can be made to minimize host writes, like disabling (or moving to another partition) the pagination file, which should have only a minor impact on performance since you have plenty of RAM for a "normal" use but... What is the point of having a SSD then? Access times are more than an order of magnitude faster than mechanical HDD, and in RAM impaired scenarios is a big performance improvement having the pagefile on flash memory.

Just check the value again in 1 month if that gives you peace of mind. Do not worry, modern OSes and controllers are pretty smart about preserving SSD health.