${KEY_CMD+KEY_V}
works well on the Mac, but you need to make sure you have latest RealUser XModule Version V1.0.12 (and not the old V1.0.0). See here:
my test:
{
"Name": "1count",
"CreationDate": "2019-3-1",
"Commands": [
{
"Command": "open",
"Target": "https://charactercounttool.com/",
"Value": ""
},
{
"Command": "type",
"Target": "id=textbox",
"Value": "test1"
},
{
"Command": "store",
"Target": "copy and PASTE works!",
"Value": "!clipboard"
},
{
"Command": "XClick",
"Target": "id=textbox",
"Value": ""
},
{
"Command": "XType",
"Target": "${KEY_CMD+KEY_V}",
"Value": ""
}
]
}