The site is experiencing technical difficulties on WordPress imported media

Hello, my site has about 550 media files.
It is hosted on a very powerful dedicated server.
Php and webserver are set to allow long timeouts and big file uploads.

When I export the media using the wordpress export built in feature, it exports a file big about 100MB.

When I try to import it on a new, clean wordpress, the server imports the file, then asks to choose if I want to import also the media, then when I click import, the script crashes and appears “The site is experiencing technical difficulties.”

The logs say

[19-Aug-2020 10:05:13 UTC] PHP Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 4596768 bytes) in /var/www/html/wp-content/plugins/wp-smushit/core/modules/class-wp-smush-helper.php on line 40

The problem is that it seems that smush adds a lot of line to the export WXR xml file.

There is a plenty of such lines.

							<wp:postmeta>
		<wp:meta_key><![CDATA[wp-smpro-smush-data]]></wp:meta_key>
		<wp:meta_value><![CDATA[a:2:{s:5:"stats";a:8:{s:7:"percent";d:1.6537004602663843;s:5:"bytes";i:406;s:11:"size_before";i:24551;s:10:"size_after";i:24145;s:4:"time";d:0.04;s:11:"api_version";s:3:"1.0";s:5:"lossy";b:0;s:9:"keep_exif";i:0;}s:5:"sizes";a:2:{s:9:"thumbnail";O:8:"stdClass":5:{s:7:"percent";i:0;s:5:"bytes";i:0;s:11:"size_before";i:6048;s:10:"size_after";i:6048;s:4:"time";d:0.01;}s:6:"medium";O:8:"stdClass":5:{s:7:"percent";d:2.19;s:5:"bytes";i:406;s:11:"size_before";i:18503;s:10:"size_after";i:18097;s:4:"time";d:0.03;}}}]]></wp:meta_value>
		</wp:postmeta>

It seems to work only if I split manually this big xml into smaller ones.

What is all this information about, and why it gets saved into the export file?
Is there any way to disable the export of such information?

Regards