It isn’t clear to me if you are inquiring about R code for multi-level modeling or summarizing person-level variables to create PUMA-level measures for your analyses. Our team will answer questions about data or resources available through IPUMS, but leaves analytical decisions about defining models and the most appropriate code to use to individual researchers. You may be interested in this information about multi-level modeling in R or summarizing by group in R using the dplyr package. Consulting the relevant literature for approaches on the type of model you are interested in conducting, the ACS data users forum, or R user forums may also be a good place to start.
As you mentioned, R packages survey and srvyr can help facilitate specification of sample design with the ipumsr package. This forum post has a discussion on using the srvyr package along with some sample code.