Flutter how to add a delay when input is focused? - flutter

Question

My problem:
I need to add a delay for about 100 milliseconds because the inherited animation of the TextFormField when it gets focused shows the keyboard at almost the same time the building animation of itself is running (and also because I want to apply some animations in between and/or then chain the keyboard to it).
I would like to add a small delay there.
What did I have tried so far:
I have been doing a lot things to reproduce this behavior but with not much success, I tried several strategies from flutter community since adding delays, listen to the keyboard using several packages or listening the context bottom viewPadding, I have attached listeners to the onTap of the TextFormField class and it is not the best outcome.
I also have tried with this strategy, but is not good either (sometimes there's a race between the native and the instruction that flutter has internally to show it):
// flutter hook
useEffect(() {
void focusListener() {
// FOCUS:
if (focusNode.hasFocus) {
// #1. Using SystemChannels.textInput:
// The problem with this approach is that flutter ignores it,
// it gets never hidden.
// ... skipped by brevity ...
SystemChannels.textInput.invokeMethod('TextInput.hide')
// ... skipped by brevity ...
// #2. Delay in hide & show events:
// This approach hide the keyboard but its always visible at the beginning
// for a really short amount of time, that's like a blink
// and it doesn't look nice, but this kind of
// solve the issue.
// ... skipped by brevity ...
final channel = SystemChannels.textInput;
Future.delayed(Duration(seconds: 0), () {
channel.invokeMethod('TextInput.hide').whenComplete(() {
Future.delayed(Duration(milliseconds: 400), () {
channel.invokeMethod('TextInput.show');
});
});
});
// ... skipped by brevity ...
// #3. Delay in show event:
// This approach is similar to the previous but the order
// from the channel 'TextInput.hide' is skipped
// because of the same reason of the first approach.
// ... skipped by brevity ...
channel.invokeMethod('TextInput.hide').whenComplete(() {
Future.delayed(Duration(milliseconds: 400), () {
channel.invokeMethod('TextInput.show');
});
});
// ... skipped by brevity ...
}
// VALIDATION:
autovalidate.value = focusNode.hasFocus;
}
focusNode.addListener(focusListener);
return () => focusNode.removeListener(focusListener);
}, [focusNode.hasFocus]);
Any idea?