Is it possible to change a setting or something in order to open files in existing Mathematica instances instead of in a new instances when double clicking the file. (This is convenient since Mathematica limits the number of instances that are allowed to open based on the license.)
Using the command line a solution was proposed in https://mathematica.stackexchange.com/a/13610/45020 however that question does not go into how to achieve the same thing in through a file explorer through double clicking / open with.
This question is similar but was considered a duplicate of the question in the first link because it didn't emphasize that it was looking for a graphical interface solution and not a command line one.
I use Ubuntu 20.04 with Nemo 4.42 as my file explorer.