My employer provides experience letter with roles and responsibilities clearly stated. They just don't provide any explicit support for PR - like PNP sponsorship or offer letter with 1 year's employment guaranteed. It is pretty much a standard practice across all large IT multinationals.If you REALLY have 460, I think you might be lucky to be honest. EE draw scores are coming down very fast. So if they keep inviting 7,000-10,000 people per draw, I can see the pool rapidly diminishing into the 450-470 range in the near future. Your problem then will be providing a work experience letter upon getting an invite if I interpreted correctly that your employer doesn't want to give any letter. I have a feeling you may be lucky, you're only 21 points away.
I have 460 because I was able to score NCLC 7 score in TCF.