Open bound-nested-calls.arcadia. In Behavior select OA Nested pressure checks, SA Nested pressure checks, or OA Reentrant pressure review. Each has two lifelines and four rows ordered C1,C2,R2,R1. C1 requests 420.0 kPa and R1 returns 418.0; C2 requests 380.0 and R2 returns 378.0. The SA messages resolve an actual synchronous interface-operation allocation; Replies derive it from their exact Calls. OA uses a bound Interaction carrying an Operation item without SA-only OperationUse. The reentrant case uses an explicit reverse Interaction for C2/R2. Check unselected bars, both reply ends, each bar's selection, Properties values/correlation, source parity and save/reopen. scenario-identities.tsv lists every UI target UUID. diagnostics.txt records completeness warnings. Generator validation and roundtrip are not desktop paint or native acceptance.