The European variant of the LG V40 ThinQ is scheduled to receive its stable Android 10 update in Q3 2020, while the company is planning to deliver the same a bit early in their home country. Matter of fact, LG has already published the Android 10 kernel source code for this device, which clearly indicates that the development stage is over. Confirming the speculation, the AT&T variant of the LG V40 (LM-V405UA) has now picked up the Android 10 OTA.
While AT&T itself has yet to officially list the new build on their device-specific update tracker, several users on our forums have confirmed that they’ve started receiving the update on their units. The software version of the Android 10 firmware is V405UA30b, which is a rather a steep jump from the last Android Pie-based build from AT&T, i.e. V405UA21a. The update should introduce all the new features that Google delivers with Android 10, like gesture navigation and smart replies, but the lack of a proper changelog has made it difficult to list these enhancements as well as the Android security patch level of the new build.
It is worth mentioning that the LM-V405UA model of the LG V40 ThinQ is being used by both Verizon and Sprint, thus cross-flashing the aforementioned Android 10 firmware on those carrier variants is theoretically possible. The T-Mobile variant, despite being entirely different (LM-V405TAB), should also receive the taste of Android 10 pretty soon, as LG has uploaded the corresponding kernel source code on their repository.
In case you are not satisfied with LG’s custom skin, LG UX 9.0, and want to give vanilla Android 10 a try, you can flash unofficial builds of Lineage OS 17.0 or Paranoid Android Quartz on your LG V40 ThinQ. Don't worry about the restriction on bootloader unlocking, as most of the US carrier variants of this phone (except the T-Mobile one) can be unlocked with the help of a leaked engineering bootloader.
Thanks to Reddit user u/gunnermcgavin for the screenshot!