I believed you can also use " nei 164.1.13.3 ttl-security hops 254" on r1; it set the min incoming ttl to 1 and outgoing ttl to 255 which will settle r3's incoming ttl 254 requirement.
*Mar 13 05:15:13.559: %BGP-5-ADJCHANGE: neighbor 164.1.13.3 Up
Connection is ECN Disabled, Mininum incoming TTL 1, Outgoing TTL 255
Local host: 164.1.13.1, Local port: 37159
Foreign host: 164.1.13.3, Foreign port: 179
Comments?