Is it okay to use a separate URL page for each keyword to optimize?

Right now, given that I achieved good rankings for my top keywords, I am now working on the optimization of my secondary keywords that are less competitive. Some of these are Long Tail Keywords, some are not.

I have listed about 100 of these secondary keywords to optimize and achieve rankings for. I just checked the current rankings, and only 25 of those 100 are listed in the top 100. So that means that there is a lot of space for development and improvement.

What my SEO developer suggested is to create a URL page per each keyword to optimize, which will look like this:

www.website.com/keyword1
www.website.com/keyword2
www.website.com/keyword3

and so on for all 100 secondary keywords

In the different pages, each page would be identical to the main home page (www.website.com). The only thing that will be changed is the title tag, meta tag, H1 header, 500 word keyword dense welcome message, anchor text links in the article, etc.

We would be manually creating a unique 500 word keyword dense welcome message per each keyword to optimize.

The layout, menu, banner, etc would be just exactly the same as the home page.

The question is, is this okay for Google? My concern is that I wanted to take a clean approach to this in order not to be flagged by Google, given that we spent thousands of dollars so far in SEO development, and I don't want to risk the high rankings for the primary keywords that we obtained already.

Thanks in advance!