This may appear to be a daft question to some of you specialist, but why do we have main tank and a co-located split supply tank? Why not have a split main tank with gaps in the baffle feeding the engines?
Even though it is a Part 27 aircraft it does have a Cat A Supplement so it must meet most of the design requirements of Part 29 Cat A as there are no criteria within Part 27.
Therefore -
29.903 Engines.
(b) Category A; engine isolation. For each category A rotorcraft, the powerplants must be arranged and isolated from each other to allow operation, in at least one configuration, so that the failure or malfunction of any engine, or the failure of any system that can affect any engine, will not—
(1) Prevent the continued safe operation of the remaining engines; or
(2) Require immediate action, other than normal pilot action with primary flight controls, by any crewmember to maintain safe operation.
29.953 Fuel system independence.
(a) For category A rotorcraft—
(1) The fuel system must meet the requirements of §29.903(b); and
(2) Unless other provisions are made to meet paragraph (a)(1) of this section, the fuel system must allow fuel to be supplied to each engine through a system independent of those parts of each system supplying fuel to other engines.
With the usual caveats -