Fiscal-year-start macro missing (@YearStart uses calendar year, not fiscal calendar)

You're right, @YearStart is hardcoded to calendar year (01/01) — it doesn't look at the Master Financial Calendar at all, even though @PeriodStart and @QuarterStart do respect it. This trips up a lot of people with non-calendar fiscal years, it's a known inconsistency.

There's no direct fiscal-year-start macro for this today, so filtering on FinPeriodID is indeed the standard workaround. A couple of ways to do it depending on what you need:

Option 1 — Simple, if you just need "current FY":
Filter on the first 4 characters of FinPeriodID (the year portion) matching the current fiscal year, something like:
Left(GLTran.FinPeriodID, 4) = Left(@PeriodStart(0)... ) — or more simply, derive the fiscal year from @PeriodStart using a substring, since that macro already resolves correctly against your fiscal calendar.

Option 2 — Cleaner, more reliable:
Use the Master Financial Calendar (Finance > Configuration) to pull Period 01 of the current fiscal year directly, and reference that FinPeriodID in your filter instead of trying to derive a date. This avoids any string-manipulation issues and is easier for others to read later.

Option 3:
If this is for a dashboard/GI you'll reuse often, consider adding a small unbound field or a stored procedure/view that calculates fiscal year start explicitly using the Master Financial Calendar table (MasterFinCalendar), then reference that field in your filter. More setup up front, but zero ambiguity going forward.

Worth submitting this as an idea on the Acumatica Ideas portal too — a proper @FiscalYearStart macro seems like a reasonable ask given fiscal periods already work correctly.