Reducing the load on the server

During the import process, there is often a reset and a notification that the server stops loading my import. I checked with the hosting provider and they told me the following:
They checked the logs of my site and in the file wp-content/uploads/wc-logs/fatal-errors-2020-11-30-e08ee8e05e1d9b9098f098ddcd51778b.log found notifications related to forced shutdown of scripts due to reaching the limit on RAM consumption:

2020-11-30T14:35:39+00:00 CRITICAL Out of memory (allocated 10485760) (tried to allocate 2097160 bytes) в /var/www/u0356528/data/www/look-catalog.ru/wp-includes/functions.php
185.8.7.226 - - [30/Nov/2020:17:35:38 +0300] "GET /wp-admin/admin.php?page=pmxi-admin-import&action=process&id=6&failures=0&_wpnonce=fe7b484183 HTTP/1.0" 500 6045 "https://look-catalog.ru/wp-admin/admin.php?page=pmxi-admin-manage&id=6&action=update" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36"

The hosting rates have a 1 GB limit on the script’s memory consumption. If the script tries to allocate more memory, it will be finished, which is what happens in your case.

The error occurs when executing a WordPress system function:

                // The (resized) image files would have name and extension, and will be in the uploads dir.
                if ( $name && $ext && @is_dir( $dir ) && false !== strpos( $dir, $upload_dir['basedir'] ) ) {
                        // List of all files and directories contained in $dir.
                        $files = @scandir( $dir );

They also recommended contacting the developers of the WP All Import plugin to find out what settings can be made on the site to reduce RAM consumption and solve errors.

All I did to optimize is:
Import Speed Optimization
In each iteration, process – 17 records.
Split file up into 1000 record chunks.
Increase speed by disabling do_action calls in wp_insert_post during import.

Can you tell me what else I can do?