What does the rest of your system and venue look like? This would be most helpful. This is really a system question. There is a place to put your system photo and components. So you only need do it once.
From what you say… with such very efficient speakers I would guess no. I would dedicate additional funds to upgrading a component. Component upgrade will bring greater detail, musicality… probably much greater improvement than a tiny bit more slam from adding another amp.
Even if I was to upgrade an amp… I would buy true mono-blocks. Bridging only adds power and maybe reduces cross talk a tiny bit. I am currently running mono blocks and have the same designed stereo amp.