The LTA is not an elite set-up. It has only ever produced also-rans. Andy Murray is an exception as a British player. But I don't think anyone claims he was produced by the LTA. Using the LTA as a catch-all to avoid paying the high fees demanded by the very best is, in my view, a short-sighted decision which is likely to delay or even derail Emma's development. I agree Cayer seems to be very good at what he does (crucially, he trained in Canada, not England). But he cannot commit to her full time, and even if she thinks she doesn't need a coach, I don't agree. I think your first year on the tour is not the time to wing it and develop bad habits that may be impossible to undo later. She should find an expert to keep a close eye on her, and follow closely that expert's advice.
There is plenty of room for improvement in Emma's strength and conditioning, match preparation, tactics, shot making, shot selection, mental focus, mental strength. She is far from the finished package. I hope she has the humility to realise that with her base talent, the sky is the limit - if she gets good coaching.