Feature Request: Allow copying 'balances' to another contract

For token swaps it would be very helpful to be able to copy balances from one token contract to another. I tried it out but it doesn't work.

Token1

# LST001
balances = Hash(default_value=0)

# LST002
metadata = Hash()

@construct
def seed():
    # LST001 - MINT SUPPLY to wallet that submits the contract
    balances[ctx.caller] = 1_000_000

    # LST002
    metadata['token_name'] = "MY TOKEN NAME"
    metadata['token_symbol'] = "TKN"
    metadata['operator'] = ctx.caller

# LST002
@export
def change_metadata(key: str, value: Any):
    assert ctx.caller == metadata['operator'], 'Only operator can set metadata!'
    metadata[key] = value

# LST001
@export
def transfer(amount: float, to: str):
    assert amount > 0, 'Cannot send negative balances!'
    assert balances[ctx.caller] >= amount, 'Not enough coins to send!'

    balances[ctx.caller] -= amount
    balances[to] += amount

# LST001
@export
def approve(amount: float, to: str):
    assert amount > 0, 'Cannot send negative balances!'
    balances[ctx.caller, to] += amount

# LST001
@export
def transfer_from(amount: float, to: str, main_account: str):
    assert amount > 0, 'Cannot send negative balances!'
    assert balances[main_account, ctx.caller] >= amount, 'Not enough coins approved to send! You have {} and are trying to spend {}'\
        .format(balances[main_account, ctx.caller], amount)
    assert balances[main_account] >= amount, 'Not enough coins to send!'

    balances[main_account, ctx.caller] -= amount
    balances[main_account] -= amount
    balances[to] += amount

@export
def export_balances():
    return balances.get()

Token2

# LST001
balances = Hash(default_value=0)

# LST002
metadata = Hash()

@construct
def seed():
    # LST001 - MINT SUPPLY to wallet that submits the contract
    balances[ctx.caller] = 1_000_000

    # LST002
    metadata['token_name'] = "MY TOKEN NAME"
    metadata['token_symbol'] = "TKN"
    metadata['operator'] = ctx.caller

# LST002
@export
def change_metadata(key: str, value: Any):
    assert ctx.caller == metadata['operator'], 'Only operator can set metadata!'
    metadata[key] = value

# LST001
@export
def transfer(amount: float, to: str):
    assert amount > 0, 'Cannot send negative balances!'
    assert balances[ctx.caller] >= amount, 'Not enough coins to send!'

    balances[ctx.caller] -= amount
    balances[to] += amount

# LST001
@export
def approve(amount: float, to: str):
    assert amount > 0, 'Cannot send negative balances!'
    balances[ctx.caller, to] += amount

# LST001
@export
def transfer_from(amount: float, to: str, main_account: str):
    assert amount > 0, 'Cannot send negative balances!'
    assert balances[main_account, ctx.caller] >= amount, 'Not enough coins approved to send! You have {} and are trying to spend {}'\
        .format(balances[main_account, ctx.caller], amount)
    assert balances[main_account] >= amount, 'Not enough coins to send!'

    balances[main_account, ctx.caller] -= amount
    balances[main_account] -= amount
    balances[to] += amount

@export
def import_balances(token_contract: str):
    b = I.import_module(token_contract).export_balances()
    balances.set(b.get())

If i execute import_balances() in the Token2 contract by providing the token contract of Token1 the transaction goes through without errors but balances are not copied.

This is basically the same requirement: https://github.com/Lamden/contracting/issues/303