I recently changed all the title tags on a set of pages to be:[power word] [secondary keyword] [primary keyword] [secondary keywords...]

It was previously:

[secondary keyword] [primary keyword] [secondary keywords...]

I read this would give me a good shot of extra clicks from the SERPs. The result is the opposite, a slight decline.

Overall impressions in the SERPs have increased by about 7-8%, while clicks have decline about 1-2%.

Impressions have increased sue to some on-pages changes, which have increased positions 0 results.

So this, from my test, seems to be quite a poor method.

Console:

https://i.ibb.co/cgWTGBj/Screenshot-at-2019-12-12-17-01-48.png

Decline it traffic at the beginning is due to a considerable injection from articles in news sites leading to secondary searches.