Conflict with Smart Trim module

Problem/Motivation

Markdown Easy doesn't play nicely with Smart Trim → module. This is mainly due to the order that filters are applied in a text format.

Steps to reproduce

We need this - would be a nice way for a novice to get a contribution credit (hint hint).

I played with this issue a bit a few weeks ago and left myself the following notes, but haven't followed up on it yet.

To test, add the following
// Add this to avoid Markdown filter issue?
// $rendered_output = check_markup($output, $item->format);
// $output = $rendered_output->__toString();

Right before
// Process additional options (currently only HTML on/off).
if (!empty($setting_trim_options)) {

In
public function viewElements(FieldItemListInterface $items, $langcode = NULL): array {

Proposed resolution

Make the two filters play nicely together.

Remaining tasks

All of them (other than creating this issue).