Nope, you still need to do it manually. But I think you can ease your work with this 
{
"id": "mon_zombie",
"type": "MONSTER",
"copy-from": "mon_zombie",
"delete": { "flags": [
"SEES",
"HEARS",
"SMELLS",
"STUMBLES",
"WARM",
"BASHES",
"GROUP_BASH",
"POISON",
"BLEED",
"NO_BREATHE",
"REVIVES",
"PUSH_MON",
"FILTHY"
] },
"extend": { "flags": [
"SEES",
"HEARS",
"SMELLS",
"STUMBLES",
"WARM",
"BASHES",
"GROUP_BASH",
"POISON",
"BLEED",
"NO_BREATHE",
"REVIVES",
"PUSH_MON"
] }
}
Wherein "delete" is the monster’s original flags and "extend" is the modified one 