When using a form, you can pre-fill linked fields in forms by using the Record ID for the record you want into a single line text field instead of the actual name, then use Zapier, IFTTT, or (my personal favorite) Integromat to update the linked field with that record ID. I realize it’s cumbersome, but you just have to have it, it works. I do this for several of my forms.
Thanks for this tip. That could be really useful going forward for a scenario I have where users add order lines to an an order and have to link the order line to the main order record.
One question on tritggering the integration, does the action which copies the data between the fields run on a timed basis, or can it be triggered by data going in?