I would like to be able to allocate different payments (on account) and invoices through the 'new batch payment', meaning that it would also show unallocated payments and not just invoices. Both creditors and debtors.

One could allocate one payment done for different invoices after having posted it on accounts (something invoices are received after). As else I would have to delete the payment and re-post it but this is not possible when the reconciliation would have been closed.