i3: is 0:_NET_WM_STATE@:32a *= _NET_WM_STATE_HIDDEN still needed?

Readme states:
> If you use i3, the following is also required for flashfocus to work with tabbed containers:
>opacity-rule = [
> "0:_NET_WM_STATE@:32a *= '_NET_WM_STATE_HIDDEN'"
>];

1. is this rule still needed?
2. if given rule is added to the config, then picom logs:
> c2_parse_target WARN ] Type specifier is deprecated. Type "a" specified on target "_NET_WM_STATE" will be ignored, you can remove it.

picom v12.5, [flashfocus 2.4.1](https://pypi.org/project/flashfocus/)