How to combine queries on Cayenne.api?

In my project there are a lot of sensors (about 15) that have to be processed using a bunch of the same type
client.virtualWrite(301, var_ch_301, "digital_sensor", "d")
which all have to be sent at the same time. If the Internet is not very good - this may be a problem.

Is it possible for the API to transmit values from several sensors simultaneously in one request, combining them?
Or maybe someone can tell how to do this without a standard library?

And one more question:
I have a slider in the project, when I change its values, I process them using the construct:

def on_message(message):
global var_ch_103, var_ch_104
print("new var_ch_103 value: " + str(var_ch_103))
print("new var_ch_104 value: " + str(var_ch_104))
return 1

But for some reason, the values come through time :frowning:
Maybe I should accept the parameters in some other way, or send a confirmation of receipt immediately?

each widget data needs to be published individual. it wont be an issue for sending 15 sensor data together in CAYENNE_OUT_DEFAULT()

    print("message received: " + str(message))
    if ( == 4) and (message.value == "1"):