SIMPLELINK-CC2640R2-SDK: SDK v1.40 and SDK v1.50 differences?

Part Number:SIMPLELINK-CC2640R2-SDK

Hi,

    I just recently downloaded SDK v1.50 and I would like to know what is the difference from SDK v1.40. Here are some questions below.

1. SDK v1.50 Off-Chip OAD App only download time is very fast at 20 seconds, However using SDK v1.40 Off-Chip OAD App only takes 3 minutes to finish. What are the improvements at SDK v1.50 Off-Chip OAD example program that able to achieve fast OAD download time of 20 seconds?
2. Why is that the SDK v1.50 does not have BLE 5 Stack included?
3. What bug fixes have been done at SDK v1.50?

-kel