Are there any parameters regarding Alarm Summary/SOE Display for Citect SCADA V7.40 ?

Here is the default row size which can be changed as per requirement. It has some impact too on the performance. So better to prescribe a system with higher specifications like 64 bit processor with a clock speed of more than 3 Ghz and max ram if available to avoid any performance issues. I checked the document you attached from the help file. It's more related to troubleshooting in case you don't see events on the page. But this is not always the case & it's for reference to troubleshoot.
Alarm.<ClusterName>.<ServerName>QueryRowLimit
Define the maximum number of rows that can be returned in the result set for a single query.
Increasing the QueryRowLimit may affect performance.
Allowable Values: 0 to 4294967295
DefaultValue: 200000
For alarm summaries, we have a parameter like you may control this parameter to make available the of records and set time for a number of days to make it available for
display on the summary page for viewing purposes after this timeout period it will be moved out of the summary page and will still be available inside log files.

[Alarm]SummaryLength
The maximum number of alarm summary entries that can be held in memory. The maximum number for this parameter has been modified from 4096000 to 100000.

[Alarm]SummaryTimeout
The length of time that alarm summary entries remain in the alarm summary queue.

You can disable this parameter by setting it to -1.

Note: This parameter is modified by the Computer Setup Wizard as well as the Computer Setup Editor.

Allowable Values: 0 to 20000 (minutes)

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