Also note that sometimes editing the CPTs directly caused an out of memory problem due to an infinitely descending loop of action hooks the_content and pre_render_block.

I'm going to raise this as a separate issue to see if this is something I've done or a problem with Gutenberg itself.

Originally posted by @bobbingwide in #1 (comment)

Problem

• Attempting to use Appearance > Templates to edit a specific template part can lead to a timeout / memory exhausted issue.

With oik-bwtrace activated I got

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 585728 bytes) in C:\apache\htdocs\wordpress\wp-content\plugins\oik-bwtrace\includes\class-BW-trace-record.php on line 191

The trace log file was 364MB. The call stack at the end of the trace file was 3647 functions deep.