If you do as you said, in the end it will simply be loaded default model specified in the blockstate. OBJ model is not loaded at all...
{
"forge_marker": 1,
"defaults": {
"model": "realism:beton"
},
"variants": {
"normal": [
{
}
],
"inventory": [
{
}
],
"multi": {
"invalid": {
"model": "realism:beton"
},
"center":{},
"render": {
"custom": {
"flip-v": true
},
"model": "realism:testobj.obj",
"transform": {
"scale": [
1,
1,
1
],
"translation": [
0.5,
0,
0.5
]
}
},
"structure": {
}
}
}
}