Summarize with dynamic variable involved

consider the following option:

datatable(key:long, Timestamp:datetime, d:dynamic)
[
    1234, datetime(2019-07-24 23:59:33), dynamic({"isA":false,"isRR":false,"isE":true, "isM":null,"isVS":0,   "isBot":false}),
    3938, datetime(2019-07-24 12:04:32), dynamic({"isA":true, "isRR":false,"isE":false,"isM":null,"isVS":1000,"isBot":false}),
    3982, datetime(2019-07-24 01:33:13), dynamic({"isA":false,"isRR":true, "isE":false,"isM":null,"isVS":0,   "isBot":true })
]
| summarize count_key = dcount(key), 
            count_key_where_isA_is_true = dcountif(key, d.isA == true),
            count_key_where_isRR_is_true = dcountif(key, d.isRR == true)
         by Date = startofday(Timestamp)