It is recommended to avoid using the maxLength attribute in ROAs. See BCP 185. https://www.rfc-editor.org/info/rfc9319/
Wait, what?!? Is that just a wording issue, or did I totally mis-understand the whole purpose of RPKI ROAs? I'll have to admit that I've not looked too closely under the covers, but to my mind, if I originate 192.168.0.0/16 into the routing system, and do not want to authorize any longer routes in this address space than this /16, do I not then use the maxLength attribute to say "16"? That's certainly what it looks like to me through the RIPE NCC RPKI ROA issuance assistant... So isn't then the recommendation of BCP 185 to not authorize "too many" un-announced prefixes by having a large difference between the prefix length and maxLength in ROAs, rather than discouraging the use of maxLength altogether? Best regards, - Håvard