Why take
t_i = \alpha + \beta \cdot x_i + \epsilon, \quad \epsilon \sim \textrm{lognormal}(\nu, \sigma)
rather than the more traditional log-linear regression,
t_i \sim \textrm{lognormal}(\alpha + \beta \cdot x_i, \sigma).
I would be surprised if BRMS used the OP’s formulation rather than standard loglinear regression.
The Wikipedia isn’t very helpful here, but this is what I’m talking about: Log-linear model - Wikipedia
The previous post on this topic was never answered. :-(