This “fatal flaw” is inherent of all battery-powered devices. Just as @JDRoberts has described, the reporting frequency is limited so it can extend its battery life. @Mariano_Colmenarejo gives more explanation in this post:
Concerning the Shelly Plus H&T sensor, I wanted to add some information about the device’s technical specifications. According to the Shelly representative, the sensor will report humidity values between 0-100% but is only recommended for use within environmental humidity conditions that do not exceed 70%. What a peculiar design. 
The only other plug-in temp/humidity sensor that I’ve been able to find is the IKEA Vindstyrka air quality sensor but it’s only partially functional since there isn’t an edge driver for it.
As for the Aeotec AerQ, in addition to the RH limit of 80%, you will have the same problem with its reporting interval because it’s battery-powered. From my personal experience with the AerQ, beware that it does not accept offset adjustments as easily as my Zigbee devices with similar offset options.
Currently I am in the same boat; searching for an accurate, plug-in temperature/humidity sensor with offset parameters.