We noticed some our mass production device units based on tlsr8258 chip work unstable, if we run main clock at 48 MHz (use doubling of external 24M crystal). The issue is device performing random SW reboot in the time gap between 10sec-10min when device is keep connected to bluetooth smartphone. The problem is gone, if we rebuild with 24 MHz clock (but our app then can't fit performance requirement for some of the task), or we are not connecting via Bluetooth (performs just advertising). 
On some patch notes for 3.4.2.1 SDK (namely, patch 0006 claims improvement on 48M mode):

## V3.4.2.1_Patch_0006
### Features
* SDK version：telink_b85m_ble_single_connection_sdk_v3.4.2.1_patch_0006.
* Support P25Q80U for B87.
### Bug Fixes
* Fix an issue that very few B85-chips may run abnormally when the clock is 48M.

Our development current SDK is 3.4.2.1 with patch 0004. But we can't find link for 3.4.2.1 SDK with patch 0006. On Telink Wiki it is already 3.4.2.2 (with different precompiled *.a projlib/ files). Can we somehow obtain info on how to rework clock initialization of 48 MHz (make it more like int patch 0006)? So we try and see if it helps. For now we are not ready to make big migration to new 3.4.2.2, because it will require a lot more time-consuming and mass production device tests.