If people wanted to do a UBI I would recommend the revenue dispersed not be from taxation its self. As you dont want to cripple a hopefully growing economy. However I would suggest more of a taxation at first on citizens to use that money as capital on a government business. This way the government owns the business because of the taxation and then once the business is generating a surplus of money. It can put a percentage of the surplus back into further growth of that business and a percentage of surplus into a UBI setting. This way taxation doesnt continually increase for UBI but UBI payments increase based off the surplus of revenue of the business. Governments could have multiple industries if they wanted to have a larger UBI in total or because they want the initial government funded industries to have a larger percentage to be put back into the business.
On a side note I'm wary of this UBI. Who would get it? Only people in your settlement that are citizens? Only the initial investors of taxation? The travelers? How would payments be handed out? Etc. I'm neither pro or against it. Just think it should be carefully considered as total economic collapse could happen if done incorrectly.