Enter expense entry screen has no "Payment mode" ?

All expense payments  default to the payment mode used in invoice payments, so all expenses entered have no choice but to accept this mode.

I've used a custom field for this selection but it should not be necessary.

A "payment mode" should be available on the entry screen, impossible to record the correct mode for those that pay expenses with different payment methods !

On another note - Can we expect validation rules for expenses ?