Supported Optics

I am wondering about support for an ER (extended range) optic for a F5 5050. I found a document about F5 optics and it showed an ER but it says they no longer make it and it was only supported in one piece of hardware. I have some Curvature ERs but when I put them in I get unsupported optic in the log. Can I just power though, will it work? Or do I need a F5 branded left-handed smoke shifter? I am right on the edge of an LR but the loss is fairly high. Other equipment that I have covering this distance seems to work rather will with ERs but can by spotty with LRs. Thanks in advance. Joe