ARA support would (afaik) allow synthV’s vst to allow tighter integration with the daw transport for daws other than reaper. According to a list I found on the interweb, the daw list that supports ara has grown.
Studio One 4 (ARA2/1), Studio One 3/2.5 (ARA1)
Logic X 10.4.3 (ARA2)
REAPER 5.97 (ARA2)
Cubase 10, Nuendo 10 (ARA2)
Tracktion Waveform (ARA1) - Since v10 - ARA2
Cakewalk/Bandlab SONAR (ARA1) - (seems like) Since 2019.5 - ARA2
MAGIX Sanplitude (ARA1) - Since X5 - ARA2
Acoustica Mixcraft (ARA1) - Since 7.4 - ARA2
Pro Tools (ARA2) - Announced, no full 3P support yet
JUCE since 7.0 has Host/Plug-In support for ARA2.