The oral edaravone study estimated completion date is November of next year. Then, the company has to clean and analyze the data, write it up, and submit an NDA to the FDA, which usually takes a year or so unless they are under a program that allows for a rolling submission. Then, even under a priority review, the FDA has six months to make a decision (reject, approve, or send back for more work). So realistically even if all the stars align, we're talking mid-2023 approval.
As for trying everything, ALS is at least in part a disease of metabolism and everything you take has to be metabolized, which can literally compete with food for the energy to process it. I would also consider the safety and efficacy of combining multiple, incompletely tested rx and supplements. You can cancel out effects, make effects stronger, cause side effects, etc, and basically negate the "different mechanisms of action" notion. At a minimum, I would check them all against each other somewhere like drugs.com and check the exclusion criteria used in the trials to illuminate other possibly adverse combinations.