Okay I decided to build a hack to add this functionality myself.
Here are the steps:
1. Add "User JavaScript and CSS" extension to Chrome: https://chrome.google.com/webstore/detail/user-javascript-and-css/nbhcbdghjpllgmfilhnhkllmkecfmpld
2. Add this javascript snippet:
document.addEventListener('keydown' e => {
// Check if the entity shape editor is visible
if (!document.querySelector('lucid-erdentityblock-advanced-options')) {
return
}
// Check if the key combination pressed matches the desired keyboard shortcut
// Desired shortcut: ALT+"plus" (add row) ALT+"minus" (remove row)
if (e.altKey) {
if (e.code == 'NumpadAdd') {
// Add row
const upButton = document.querySelector('lucid-erdentityblock-advanced-options > lucid-rich-menu-item:first-child lucid-spinner .up-button')
triggerMouseEvent(upButton 'mousedown')
triggerMouseEvent(upButton 'mouseup')
}
if (e.code == 'NumpadSubtract') {
// Remove row
const downButton = document.querySelector('lucid-erdentityblock-advanced-options > lucid-rich-menu-item:first-child lucid-spinner .down-button')
triggerMouseEvent(downButton 'mousedown')
triggerMouseEvent(downButton 'mouseup')
}
}
// Helper from here: https://stackoverflow.com/questions/24025165/simulating-a-mousedown-click-mouseup-sequence-in-tampermonkey
function triggerMouseEvent (node eventType) {
var clickEvent = document.createEvent ('MouseEvents');
clickEvent.initEvent (eventType true true);
node.dispatchEvent (clickEvent);
}
} true)
3. Have fun with our new keyboard shortcuts! alt+plus to add alt+minus to remove