I think Stobart are struggling to make much profit out of SEN and are their finances are somewhat stretched. Not dissimiliar to Luton airport about 15 years ago
If the airport were to be sold by Stobart to a bigger company with deeper pockets and greater ability at extracting profit from SEN, then I imagine money could be found to buy the retail park or golf course. I very much doubt the retail park owner would object to a big pile of cash or the individual tenants being bought out of their leases when the average High Street is struggling so much