Hyperkitty interface quite slow due to sass file generation ?

Hi,

I installed mailman 3.0.3 with mailman-bundler.

I notice that when I go to /archives/ urls, it's reaaaaaally slow. Loooking at htop, I see that a CPU is 99% with a sass command:

/usr/bin/ruby /usr/bin/sass /opt/mailman/mailman-bundler/eggs/HyperKitty-1.0.3-py2.7.egg/hyperkittystatic/hyperkitty/sass/hyperkitty.scss /tmp/<something>.css

When I'm on /mailman3/ urls, I don't have this problem; interface is fluid.

Did I miss something ? Can't we build css files once for all ? Do we have to wait for 1.0.4 to have this fixed ?

Thanks, Nicolas