Kristof, I can understand 'big company mentality'. However, if they can't afford to 'donate' a board(s) for the purpose of developing the needed changes to OpenOCD, then asking someone to purchase a board and donate their time to do the changes is probably expecting too much.
I was in a similar situation, however, the company I made the OpenOCD changes for provided me with the appropriate boards. While this didn't compensate me for my time to do the changes, at least it added the OpenOCD code base. Regards, Jim