Analyzing method comparison studies that include repeated measurements

I am currently a graduate student working on my thesis, trying to analyze method comparison studies that include repeated measurements. I have a dataset created in the context of a method comparison study, and we are trying to determine agreement between a point-of-care device and a gold standard (central laboratory measurement) to measure hemoglobin. Approximately half of the participants in the dataset have a single measurement with both devices done at one time point, and the other half have multiple measurements (with both devices simultaneously) done over a few hours (unbalanced repeated measures). We are familiar with Bland & Altman's Limits of Agreement method that accounts for repeated measurements, as explained in their papers from 1999 and 2007. However, we are wondering if anyone would be aware of alternate statistical methods that would be appropriate to analyze such studies that includes both participants with repeated measurements and participants with a unique measurement. Any reference to current literature would also be appreciated. Many thanks for any help you can provide!