template merge in one batch

Q Can recipe 015's three steps (claim Tasks by template_task, clear task_template, set it) run as one _batch, with the same Tasks and edges as the split sequence?

Endpoint POST /entity/_batch ; PUT /entity/shots/<id> ; POST /entity/tasks/_search ; POST /entity/task_dependencies/_search

Docs claim Silent on the order a batch applies its requests and on server-side work between them.

Actual

template tt: a@step1, b@step2, dep b on a start-to-start offset_days 1

(a) bare Shot, hand-made a@step1 (ip) and b@step2
    ONE batch [claim a, claim b, Shot task_template tt] -> 200
    2 Tasks: a template_task=tt:a ip, b template_task=tt:b wtg; dep b on a start-to-start 1
(b) Shot created with tt, generated b deleted
    ONE batch [Shot task_template null, Shot task_template tt] -> 200, rows' task_template [None, <tt>]
    2 Tasks: a, b re-created (new id); dep b on a start-to-start 1
(c) Shot created with tt, generated b deleted, hand-made b@step2 (ip) added
    ONE batch [claim b, Shot null, Shot tt] -> 200
    2 Tasks: a wtg, the hand-made b template_task=tt:b ip; dep b on a start-to-start 1
control (c) setup, split: batch claim, PUT null, PUT tt -> 200, 200, 200
    2 Tasks: a wtg, the hand-made b template_task=tt:b ip; dep b on a start-to-start 1
control (b) setup, split: PUT null, PUT tt -> 200, 200
    2 Tasks: a, b re-created; dep b on a start-to-start 1
left clean: 0 Shots, 0 Tasks, 0 templates zzprobe_098_*

Teaches

• A batch applies its requests in order and each sees the one before: a claim earlier in the batch stops the apply from duplicating that Task, exactly as when the claim is a call of its own.
• Two updates of the same field on the same record in one batch are not collapsed. null then T runs the apply, as two PUTs do (probe 084, Shot D); T alone on a Shot that holds T does not.
• The one-batch merge and recipe 015's split sequence left the same Tasks, statuses and edges; the template's edge was written onto the claimed hand-made Task in both.
• One call instead of three, and atomic: a failing claim rolls the clear and the set back with it (recipe 002). Recipe 020 is this as code.