Deploying RPKI ROV requires engineering time, so the concern about the burden placed on smaller ISPs is valid. This was a concern that was raised by the joint response from the Global Cyber Alliance and the Internet Society.
The FCC’s current proposal focuses on the largest ISPs, so at present it is unclear how this requirement could extend to smaller ISPs. There is some protection afforded to smaller ISPs that make use of transit from larger ISPs that have deployed RPKI ROV.
Keep track of routing security adoption in your country via the Pulse Country Reports.