I want to suggest to put these lights in a group ( < group > app).
Homey is not good at sending many commands at once, with the quirks you mentioned as a result.
The group app has a “delay” option, which you can set to 100ms for example.
The delay will be added between the commands to every device in the group.
Just play with the delay time, until you find the shortest workable delay.
Example of a group of lights, which presents itself as one device:
.
Your flow would then look something like this:
