I haven't booted mine up to check for updates over the weekend, but if this post is any indication (https://forum.manjaro.org/t/post-19-06-updates/92791) then we should start seeing video acceleration in 19.06. That is if Strit updated 19.06 to use kernel 5.1 or 5.2. Again, I cannot confirm this as my Pinebook is not with me, and the update to 19.06 still showed a modified 5.0 kernel in use on the Pinebook, but maybe someone else can chime in and give a more definite answer.
EDIT: Checked my Pinebook last night, Manjaro install reports using kernel 5.0.3 (I think, certainly 5.0.) If you compile a version of mainline kernel, lima, and lima-mesa, you should see some hardware acceleration.
EDIT: Checked my Pinebook last night, Manjaro install reports using kernel 5.0.3 (I think, certainly 5.0.) If you compile a version of mainline kernel, lima, and lima-mesa, you should see some hardware acceleration.