sf texei data plan generate --objects Account,Contact,MyCustomObject__c --outputdir ./data
for multiple objects its only generating one sobject
{
"excludedFields": [],
"lookupOverride": {},
"sObjects": [
{
"name": ***************************************************************************************************
"label": "",
"filters": "",
"orderBy": "",
"externalId": "",
"excludedFields": []
}
]
}