Is this the place to report issues? I've been playing the Optifine preview Optifine 1.14.4 HD U F4 pre4 with almost all releases of Forge for the past week and they both seem to work well. I occasionally get severe slowdowns and lag and have to quit/restart and all is well. The console sometimes complains of OpenGL issues - but I haven't yet posted them here.
All my mods and all the shaders I've tried work well. I'm not really acquainted with Optfine so perhaps there are settings that will improve performance. I pretty much left everything default.