Is the only purpose of tail emission to encourage continued mining in a situation where transaction fees alone are not economically sufficient to do so?
IIRC there was discussion in a Monero thread about a feature tail emission was required for, or some attack it prevented.
As long as there is some cryptonote coin with no tail emission (preserving diversity of approaches and mitigating risk) I'm fine with BBR doing it.
But absent some immediately compelling reason, I'd table the motion until
BBR's 10th birthday, then re-consider.
By then the XMR tail emission will have been reached so there will be some real world data. Good plan.