This convolution plugin Aava looks interesting - up to 4 IRs at once and you can modulate parameters of each, morph between them, turn on key tracking and/or tempo sync...
Available on the 3 typical desktop OSes so it gets the #LinuxAudio hashtag.
Aava - Viiri Audio
Aava is a groundbreaking convolution plugin that allows you to adjust all IR parameters in real-time, even at audio rates.viiri-audio.com
