Hi, I created pull request which includes solution for MYNEWT-526 and few minor fixes: https://github.com/apache/incubator-mynewt-core/pull/257
This is not a fix, more like a workaround for a known problem in older versions of TI CC254x which cannot apply connection parameters after update if CONNECT_IND was done with transmitWindowOffset set to 0 (and actually I found the same to be true for 1). By default, nothing changes in Nimble behaviour, but there is an option that allows to set minimum transmitWindowOffset used in CONNECT_IND - if iop with broken devices is required, just set BLE_LL_CONN_INIT_MIN_WIN_OFFSET to 2 or more. Best regards, Andrzej