Caveat: breaks if you start an interactive pop transition and change your mind.

FStaticNavigationBar.m

@implementation FStaticNavigationBar {
    __weak UIView *_navView;
}

- (void)layoutSubviews
{
    [super layoutSubviews];

    _navView.hidden = _staticTitleView != nil;
    if(_staticTitleView) {
        [UIView animateWithDuration:0.3 delay:0
                            options:UIViewAnimationOptionBeginFromCurrentState
                         animations:^{
            _staticTitleView.center = _navView
                                    ? _navView.center
                                    : (CGPoint) { CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds) } ;
        } completion:nil];
        [self bringSubviewToFront:_staticTitleView];
    }
}

- (void)addSubview:(nonnull UIView *)view
{
    [super addSubview:view];
    if([NSStringFromClass(view.class) isEqualToString:@"UINavigationItemView"])
        _navView = view;
}

- (void)setStaticTitleView:(UIView *)aView
{
    [_staticTitleView removeFromSuperview];
    _staticTitleView = aView;
    [self addSubview:_staticTitleView];
}
@end