To add some additional thoughts...
It isn't a matter of how long it takes to get approved by DMEPOS, generally with a paper application as opposed to doing it through PECOS is a difference of a few weeks. What IS a matter that a SSN is required, and you don't have one. There is no way to complete the application if you don't have an SSN. Well, you can complete it, but it will be rejected once they get it, unfortunately.
The waiver for the fees also doesn't matter, as eventually, the fee will have to be paid. Another consideration is the mandatory on-site inspection. These inspections have temporarily been suspended due to COVID-19, but will eventually resume.
Basically, the situation is this...DME fraud is rampant, and Medicare/NSC has put a lot of requirements into place in the last few years to prevent this fraud from occurring. So unless you are prepared to meet every requirement starting with the application,then the on-site inspection, and a few other things, don't even bother trying to become a provider. Not trying to be a Negative Nellie here, but I have done numerous DME initial applications and the subsequent follow through requirements and the re-credentialing process, and I don't see how you can even get started without an SSN.
Just my two pennies.