Will there be an effect from multiregionality in Google and other foreign PSs?

Question

Search Engine Optimization

IM in the com zone, one language - en. Assigned Region/Company: USA. Physically/officially, there are no branches/warehouses in other countries => there is no possibility to be placed in places/business/confirm information/set the region, but there are traffic/orders.
The task is to improve the rank in Uk, Au, Ca, in general, English-speaking countries.
Given the above, does it make sense to use rel alternate (your own version?) to separate users by country if the content is the same except for price differences? Opencart2 engine (maybe there is a solution/plugin).

Answer 1

when there is only one language - Google doesn’t really like sharpening for countries and rel alternate
, however, there were no such experiments in their projects, I won’t say for sure
another thing is that in Uk, Au, Ca English is far from 100%, but, let’s say, no more 90
.

Answer 2

As far as I understand, you have a com zone tied to the USA. Therefore, in order to improve the rank in Uk, Au, Ca, domains in these zones are necessary. Link sites in the webmasters console.
Then relink your site in the com zone with rel alternate and set hreflang="en-au", hreflang="en-gb", hreflang="en- us
"
/
https://www.purplebricks.com.au/
https://www.purplebricks.co.uk/