Once more thank you for the reply. Below the output of the peer and sa status. I have also attached the log, obfuscated the IPs as per the config provided and marked non-relevant IPs as x.x.x.x.
The reason for the “odd” GRE configuration stems from VyOS documentation where it is recommended to use these /32 loopback IPs to match the IPSec policies on. The a /30 network is used as a link network and also functions as the BGP peer IPs on both sides of the tunnel. I agree that my implementation on the Mikrotik side can probable be simplified or improved which I will try as per your suggestion.
SyslogCatchAll-2019-04-17 obfuscated.txt (512 KB)