I don't think it is a good idea to mix payload data and consistency mechanisms. Better keep the two split. For instance, if you want to ensure that your system

I don't think it is a good idea to mix payload data and consistency mechanisms. Better keep the two split. For instance, if you want to ensure that your system is consstent, you can identify your events in such a way that you can infer the previous in sequence (e.g. if you received event 1 and 3, you know that you've lost event 2). This way you keep two separate, simple mechanisms to deal with two problems, rather than getting one more intricated problem.