Several years ago, I got an R&R at top field. I have never resubmitted - it's a long story, so don't ask but let's just say it's combination of "I hate this paper", "I don't believe in this paper anymore" and the discovery of major problems with it. I am leaving it there because of the option value, which expires at some point but last time I checked, has not yet.
Present day - I have a new manuscript that I think would be a reasonable fit for this same journal where I have the tardy R&R.
What exactly are the downsides associated with submission that I should know of ex ante, particular with respect to how a new submission harms the old R&R, and then secondly, how it affects the current manuscript.
These have different coauthors, also, so do I have to talk to the old coauthor about this decision, and if so, precisely why is that the case? (These are all serious questions - I'm completely unsure of the etiquette involved in coauthorships, and various stuff related to publications. Rarely does it overlap with something I interact with outside the academic context, giving me less intuition).