Every time you enter you'll be stamped in for 180 days, each entry can be extended 180 days (1900 baht, it is assumed as this is the normal extension fee), or you can leave and return and be stamped in again 180 days. Nobody knows how the extension scenario will eventually play out it, it was suggested that paperwork/proof may need to be resubmitted. Right now it's recommended to bounce rather than extend.
You need to be in the country of the consulate you are applying to. You don't need to be in that country to receive the e-visa. Some people don't get their visa on time and depart from the country they applied from.
You might also need an employment certificate, basically a letter stating you are currently an employee and representing the company doing remote work.