Override reverse SharedElementTransition when onBackPressed

Question

I have 4 ImageButtons placed in a simple Layout. When I click any of these buttons, a new TabActivity is launched, and the corresponding Tab is selected (0-3). The tabs are styled with an ImageView matching one of the previous buttons each.

EDIT WITH SOME PROGRESS BELOW

TL;DR: How to set a different SharedElementTransition when returning to the calling Activity, so that the "back" transition is not a reverse of the original one, and possibly animate different Views?

I also use a SharedElementTransition to animate the ImageButton into the selected tab, which works when entering the new Activity, but if I navigate through the Fragments of the new Activity, and press the back button from a Fragment different from the one I arrived to, the reverse SharedElementTransition doesn't match the Tab I'm currently on, and it just reverses the transition used to launch the new activity.

I can see this is the expected behavior, but how can I override it? I want the reverse transition to start from the current Tab, not from the Tab I arrived at from the previous Activity.

I hope this ignominious picture helps understanding the question (it shows the behavior I want to obtain -starting new activity from the orange button, navigating to the green tab's fragment, and pressing back returning to the first activity transitioning from the green tab-):

There's no much code involved in the question, but just in case I am launching the new Activity as:

(...)
ActivityOptionsCompat options = ActivityOptionsCompat.makeSceneTransitionAnimation(fromActivity, sharedView, transitionName);
fromActivity.startActivityForResult(toIntent, requestCode, options.toBundle());

And then, in the arriving Activity, I set up the TabLayout as follows in the onCreate() method (analogous piece of code for each Tab:

tab0 = (...);
ImageView v0 = (ImageView) tab0.findViewById(R.id.tab_img);
ApiLevelHelper.setImageDrawable(this, v0, R.drawable.menu_btn_0);
tabLayout.getTabAt(0).setCustomView(tab0);

Thanks in advance

EDIT - SOME PROGRESS ACHIEVED

Well, There's still an important problem to solve, but I've managed to get the right Tab transitioning on the reverse animation. In order to achieve this, I have no transition name previously attached to the Tab's ImageViews, and I set the transition name on the onCreate() method of the new activity only to the selected Tab. Then inside the onBackPressed() call, I clear all transition names from all Tab's ImageViews, and set it to the current Tab. This way the reverse animation starts from the correct Tab, but it ends up in the original ImageView's position, instead of the new one.

What I've tried so far:

1. Clearing transition names on the first activity and setting it just to the ImageView I want to reverse-transition to, inside the onActivityResult(...) method. Sadly enough, the animation conditions seem to be stablished before this method is called.
2. Staticly referencing the parent activity (knowing this is bad, just testing) and clearing transition names and setting just the one I want before calling super.onBackPressed() from the second Activity. It didn't change anything.

Some code showing how the transition name of the current Tab is set:

//Second Activity
@Override
public void onBackPressed() {
    if (ApiLevelHelper.isAtLeast(Build.VERSION_CODES.LOLLIPOP)) {
        for (ImageView v : tabImages) {
            v.setTransitionName(null);
        }
        int selectedTab = mTabLayout.getSelectedTabPosition();
        tabImages[selectedTab].setTransitionName(getString(R.string.transition_menu_tab));
        Intent output = new Intent();
        output.putExtra("selected_tab", selectedTab);
        setResult(RESULT_OK, output);
    }

    super.onBackPressed();
}

And then, in the first Activity...:

//First Activity
//This code has no effect right now on the ending position of the transitioned view.
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQ_WHICH_TAB && data != null) {
        if (ApiLevelHelper.isAtLeast(Build.VERSION_CODES.LOLLIPOP)) {
            int selectedTab = data.getIntExtra("selected_tab", 0);
            setTransitionName(selectedTab); //This call nullifies all transition names 
                                            //and sets it back to the right ImageView. 
                                            //But it doesn't work.
        }
    }
    super.onActivityResult(requestCode, resultCode, data);
}

I think I somehow need to manipulate the previously calculated transform... still investigating.