I rang the SEAI a few months ago and they said taxi drivers no longer qualify.
A workaround would be to buy it in a mate or relatives name to get the first grant from the SEAI then transfer ownership over to yourself and apply for the NTA grant afterwards.Might be immoral buy not illegal AFAIK.
If you buy a secondhand leccy car that's a few months old off a dealer it's likely already gotten the SEAI grant so it would be stupid for them to be doing background checks.They're still really expensive experimental vehicles even with the bigger grants.