Performance Impact of increasing Max Feed Entries/page in ETM Advanced Properties
One answer
Increasing the Feed Size property does impact the application performance as it increases the amount of data being retrieved per page using APIs. However, the extent of impact would need to be evaluated in your environment as it depends on your use-case / requirement, network I/O, data shape, HW resources on the server etc.
Our suggestion is to increase the value in steps of say 50 or 100 so you can review the application performance and evaluate in your TestEnvironment before considering the change in a Production Environment.