That's really probably more to do with how long it takes to add the new samples to the database than with how fequently the updates are pushed out.
I think *this* is what the OP is talking about. The request (if I understand correctly) is not so much related to sending the updates to the users more frequently than it is done nowadays (about twice a day). This is off-topic.
The request points to, once Avast Team received the email (or any equivalent / available method to receive the sample), it should take less time to analyze it and add it to the next database update (whenever the next update would be released to users).
*I* personally don't have any real nor statistical comparison, but it seems the OP indeed has (at least for the particular encountered cases).
Since the samples from the chest are sent to Avast during the next update, it could take several hours for those samples to get to the relevant people. Using the email method (zipping and password) "should" be, generally speaking, quicker (though, I don't know which arrivals are checked "first" by Avast Team).
The key, IMHO, would be the difference in time between Avast and other security tools. If we are talking about some hours (next database update after the sample had been sent to Avast Team), fine. If we are talking about days...