php - How can I efficiently process 50k+ Gravity Forms entries without running into memory or timeout issues?

I'm working on a WordPress shortcode that aggregates data from Gravity Forms entries. I have:

• Around 50,000 entries on an enrollment form
• Around 30,000 entries on a feedback form
• Over 200 trainings
• I need to calculate averages from a few specific fields across all matching entries for each training and for all trainings as a whole

My initial thought was that I would fetch the entries once and then sort through them for each training and total them up in the process for my global averages.

The issue: Using GFAPI::get_entries() with 'page_size' => 0 or any large range quickly causes:

Allowed memory size of 1073741824 bytes exhausted (tried to allocate 20480 bytes)

When I try chunking with paging, the script then times out (shared hosting — cannot raise limits).

Here’s a simplified version of what I’m doing:

// Now let's get all of the entries
$search_criteria = [
    'status'     => 'active',
    'start_date' => $start, // Which is 2020
    'end_date'   => $end,   // Which is today
];

$enrolled_entries = [];

$chunk_size = 500;
$offset = 0;

do {
    $paging = [
        'offset'    => $offset,
        'page_size' => $chunk_size,
    ];

    $entries_chunk = GFAPI::get_entries( $enroll_form_ids, $search_criteria, [], $paging );
    if ( is_wp_error( $entries_chunk ) ) {
        break;
    }

    $enrolled_entries = array_merge( $enrolled_entries, $entries_chunk );

    $retrieved_count = count( $entries_chunk );
    $offset += $chunk_size;

} while ( $retrieved_count === $chunk_size );

I only need to calculate averages, counts, and basic stats — no need to load every field or the full entry object unless needed.

What I'm looking for:

Is there a better way to efficiently aggregate values across many Gravity Forms entries?

Is there a server-safe way to handle this in chunks, background jobs, or something similar within WordPress?

My full script can be seen here:

Thanks for any help or direction!