Sending Assisted GNSS (A-GNSS) to Bangle 2 GPS (AT6558)

There are NMEA (CAS00) and CASIC (CFG-CFG) commands that allow to clear, save and load configuration information to/from the chip internal flash.
When I turned on/off the chip, it restarted warmly. I assume it uses the main battery to keep itself warm. But you can restart it fresh even with factory settings.
I believe the second (bigger) long term DAT file is loaded between AID-INI 06 AID-INI 09 commands. The commands are not documented in the docs v3.6 and v4.2. According to AGPS C code the file does not need to be decrypted and should be loaded as is. But I did not try.
I agree that the smaller file can be pushed as is as well even with its text header that should be ignored by the chip. But this feature is not documented as well.
When I send CFG-MSG with query for MSG-GPSUTC it returns ACK-ACK (success). But it does not return the actual MSG-GPSUTC payload.

Serial2.write(new Uint8Array([186, 206, 4, 0, 6, 1, 8, 5, 255, 255, 12, 5, 5, 1]).buffer)
{ "hdr": 47822, "len": 4,
  "payload": new Uint8Array([6, 1, 0, 0]).buffer,
  "payloadBytes": new Uint8Array([6, 1, 0, 0]),
  "class": 5, "msgId": 1,
  "checkSum": new Uint8Array([10, 1, 5, 1]),
  "name": "ACK-ACK"
 }

When I pushed last 3 messages from the file I've got NACK for 0x08,0x07 and ACKs for 0x08,0x05 and 0x08,0x06

Serial2.write(new Uint8Array([0xBA,0xCE,0x48,0x00,0x08,0x0­7,0xBD,0x38,0x5C,0x4D,0xF8,0x63,0x0D,0xA­1,0xBC,0x23,0x5B,0x05,0x3D,0x0F,0xDD,0x0­E,0xE6,0xA4,0xAE,0xF2,0x9B,0x5B,0xE8,0x2­6,0x79,0x89,0x29,0x4C,0xD9,0xA6,0xFF,0xF­F,0x1D,0x32,0x72,0xFF,0x2B,0x03,0xD5,0x1­2,0x36,0x19,0x1B,0x03,0x47,0x00,0x25,0x0­0,0xF2,0x2B,0x90,0x00,0xF2,0x2B,0x00,0x0­0,0x2E,0xC7,0xFA,0xFF,0xF0,0xFF,0x00,0xE­4,0x13,0x00,0x00,0x00,0x1F,0x03,0x43,0x3­8,0xC2,0x71,0xC0,0xA1]).buffer);

Serial2.write([0xBA,0xCE,0x14,0x00,0x08,­0x05,0x92,0x19,0x66,0x90,0xFC,0xFF,0xFF,­0xFF,0xFB,0xFF,0xFF,0xFF,0x12,0x12,0x63,­0x90,0x89,0x07,0x03,0x00,0x38,0x33,0xD4,­0x25]);

Serial2.write([0xBA,0xCE,0x10,0x00,0x08,­0x06,0x47,0xF5,0xFD,0x11,0x0C,0xFF,0xFF,­0x02,0x38,0xF6,0xFD,0x0E,0x03,0x00,0x00,­0x00,0x9E,0xEA,0x03,0x2A]);