pfsrd for Unhindering Shield, emphasis added wrote:Benefit(s): You still gain a buckler’s bonus to AC even if you use your shield hand for some other purpose. When you wield a buckler, your shield hand is considered free for the purposes of casting spells, wielding weapons, and using any other abilities that require you to have a free hand or interact with your shield, such as the swashbuckler’s precise strike deed or the Weapon Finesse feat.The way I read that is it's free for wielding weapons. So you can two weapon fight while benefiting or fight with a two handed weapon just fine. Both of which you can do already, you would just lose the benefit of the buckler and take attack penalties. This feat overwrites that.
The feat is banned from PFS in its entirety because of its text.