1 - How to choose the default card to Arduino MEGA

You have to edit the file:

/generators/arduino/blocklyduino.js

line 93:

profile[“default”] = profile[“arduino_uno”];

arduino_uno arduino_mega.

2 - How to choose the default blocks categories

/utils/blocklyDuino.js line 479.

LoadIds =

// set the default toolbox if none in session
if (loadIds === undefined || loadIds === "") {
loadIds = "CAT_LOGIC,CAT_LOOPS,CAT_VARIABLES,CAT_FUNCTIONS,CAT_MATH,CAT_TEXT,CAT_ARDUINO,CAT_TECHNOZONE";
window.sessionStorage.toolboxids = loadIds;
}

LoadIds index.html line 246 “toolboxes definitions”