Error starting to use "long" item_ids with old database

I'm currently working on a site that was built in 2014/2015. Recently, I added a module that required item_ids with a length of ≈80 characters. This created the following error:

SQLSTATE[22001]: String data, right truncated: 1406 Data too long for column 'item_id' at row 1: INSERT INTO "search_api_item" ("index_id", "datasource", "item_id", "changed", "status") VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4); Array
(
    [:db_insert_placeholder_0] => temp
    [:db_insert_placeholder_1] => date_recur:node__field_date
    [:db_insert_placeholder_2] => date_recur:node__field_date/3138:en:0:2015-01-08-15-30-00--2015-01-08-18-00-00
    [:db_insert_placeholder_3] => 1733920571
    [:db_insert_placeholder_4] => 1
)

I know that the size was increased with https://www.drupal.org/project/search_api/issues/2704761 → #2704761 around alpha15. But there wasn't an update hook to match old databases with the new code.

I created a hook in one of the custom modules for the site to bring the database in line with the code:

function hook_update_N{
  $field_spec = [
    'type' => 'varchar',
    'length' => '150',
    'not null' => false,
  ];
  \Drupal::database()->schema()->changeField('search_api_item', 'item_id', 'item_id', $field_spec);
}

As alpha15 was around 9 years ago, I don't expect this to proceed further. I'm documenting my findings in case someone else needs it.