On the surface based on what you have written here, you will be unlikely to get endorsed. This ofcourse is simply my opinion. I am not God.
But wait … it may not mean you don’t qualify. It may simply be a packaging issue.
Here are a few things that may help.
Recommendation Letters - I will suggest you have 3 different recommenders writing from 3 different perspectives. One of them could be your former employer but all 3? You may want somebody else from the ecosystem or some other things you are active in to write too. They must know your work. They must also be regarded themselves as seniors in the field.
Additional Letters - you seem to be depending on Letters whereas the guide clearly explains that the letters can help give context but what they are interested in is documentary evidence.
Proof of Income is not needed. Letter of employment showing you earn high salary would be helpful. Also high salary at a Global scale and not your local ecosystem is what works better.
Outstanding Volunteer award may be good but if it is the same award given to every single volunteer then think again. Yes. If you say it is not and it is really special , think about other evidence that will help the assessors see this. For example, if you were picked out as one in 10k volunteers… that is impressive. If you were 1 of 5 volunteers… not so impressive.
That is all… I have nothing else to work with here… and therein lies the issue … typical successful applicants have much more to show for their work (whether exceptional promise or talent).
Is this really all you have ? Check on the guide for examples as I suspect you have more things you would have done. Don’t discount your impact as irrelevant to the application.
You can also check on this forum, a number of past applicants shared descriptions of what they submitted. You can also check out our eMigr8 Open Day videos on YouTube. A number of Visa Alumni spent 1.5 hours sharing what they submitted. These things may inspire you to package a better application.
Wishing you the very best.