we also have several customers with ESR48xx series in production.
Even if we wanted to replace them, that would then be Universal 5320 / 5420, they can not be delivered, so customers would be driven to suppliers that can deliver.
I really think Extreme should patch the ERS48xx firmware, this can not be a big deal as they already did it for ESR49xx which is build on the same OS BOSS (on VxWorks).
Many sites still have support contracts for the ESR48xx.
Hoping for an positive official reply,