Here is a part of the class in juce_PropertyPanel.cpp that is hard-coded and should be in the LookAndFeel:
titleHeight (sectionTitle.isNotEmpty() ? 22 : 0),
This need an entry in the lookAndFeel or a Getter/Setter becase the title is to small on mobile platforms
The section title is showing/hiding content only with "double click", could you make it toggle with "single click" on mobile Platforms (iOs) using #ifdef, Getter/Setter or LookAndFeel ?
Most of the Colours are hard-coded too in this class , an entry in the lookAndFeel would avoid me to duplicate your code.
Thanks for you help,