Alternative Footer property for a Monotouch Dialog Section that supports updating after the Initial Load. See this blog post http://munkiisoft.com/blog/archive/2015/06/10/updating-the-footer-on-a-monotouch-dialog-section.aspx

Section.cs

    /// <summary>
    /// MonoTouch Dialog Section super class
    /// </summary>
    public class Section : CrossUI.Touch.Dialog.Elements.Section
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="Section"/> class.
        /// </summary>
        public Section() : base()
        {
        }
        
        /// <summary>
        /// Initializes a new instance of the <see cref="Section"/> class.
        /// </summary>
        /// <param name="caption">The header to display</param>
        public Section(string caption) : base(caption)
        {
        }

        /// <summary>
        /// Gets or sets the bindable footer.
        /// </summary>
        /// <value>
        /// The bindable footer.
        /// </value>
        public string BindableFooter
        {
            get
            {
                return this.Footer;
            }

            set
            {
                if (this.Footer == value)
                {
                    return;
                }

                this.Footer = value;
                this.UpdateSection();
            }
        }

        /// <summary>
        /// Updates the section.
        /// </summary>
        private void UpdateSection()
        {
            RootElement rootElement = this.Parent as RootElement;

            if (rootElement != null)
            {
                // Need to get a Index\IndexPath to this Section. I have been unable to find anyway to do this other than
                // looping through the Parent's Sections looking for the Section and then taking a note of the numeric index
                int index = -1;
                foreach (CrossUI.Touch.Dialog.Elements.Section section in rootElement.Sections)
                {
                    index++;
                    if (section == this)
                    {
                        break;
                    }
                }

                if (index >= 0)
                {
                    rootElement.TableView.BeginUpdates();
                    rootElement.TableView.ReloadSections(NSIndexSet.FromIndex(index), UITableViewRowAnimation.None);
                    rootElement.TableView.EndUpdates();
                }
            }
        }
    }