Moving to 1.5.7. Currently 1.5.6. php 7.3.6 mysql 5.6.43 Quite a few mods.
I had written myself a mod to add the product location to enable me to easily find my products. In 1.5.6 I create a new table and added the products_id and products location to the table. I then change all the collect_info.php and preview_info files.

I now see that you have added new observers to the collect_info files.
I am just having trouble getting my head around how to use it to populate the data and display the data.

I already use an observer for product delete to remove the entry from the products_location table.

It looks like I can use NOTIFY_ADMIN_PRODUCT_COLLECT_INFO_EXTRA_INPUTS to display the info and allow user input.
Any pointers as to where I get the info back to update my table?
Or do i need to mod the products table to add the new field?

Any help welcome.