Diagnose high memory usage traced to a specific plugin

A WooCommerce store is throwing "Allowed memory size of 268435456 bytes exhausted"
fatal errors, specifically during bulk product imports and occasionally on category
pages with a lot of products. PHP memory_limit is already set to 256M.

HOSTING: [SiteGround GrowBig plan, memory_limit adjustable via wp-config but capped by
the hosting plan's overall PHP limit]
QUERY MONITOR / DEBUG LOG NOTES: [a related-products recommendation plugin is loading
every product in a given category into memory at once to compute recommendations,
rather than paginating or using a cached lookup table]

Work through this as a consultant tracing a memory leak, not just recommending a bigger
limit:
1. Confirm the plugin as the likely root cause given the debug notes, and explain why
   "load everything into memory to compute recommendations" is a red flag pattern
   versus a paginated query or a precomputed lookup table refreshed on a schedule.
2. Give the code-level fix if this is a custom or lightly-coded plugin: batching the
   product loop, using WP_Query with fields=>'ids' instead of full post objects, or
   caching the computed recommendation set as a transient instead of recalculating it
   on every page load.
3. If it's a closed-source commercial plugin where the code can't be touched, give the
   fallback: a setting to limit how many products it considers, or disabling the
   feature during bulk imports specifically and re-enabling after.
4. Address raising memory_limit itself: explain this treats the symptom, not the
   cause, and that SiteGround's GrowBig plan may cap the effective ceiling regardless
   of what wp-config requests, meaning this specific fix might need a hosting-plan
   upgrade, not just a config edit.
5. Flag the edge case: if this plugin's recommendations feed into a separate email
   marketing automation, disabling it during imports to stop the crashes could
   silently break that integration too, so check what else depends on it before
   turning it off.