Some suggested improvements to the card

I'm using this card in my design but have had significant difficulties with it that could be addressed with an update.
1) I cannot plug another card or a connector into this card. I'm not sure of the reason. The other card/connector is loose and there are electrical contact issues as a result. Relays don't work and i2c external expansion cards fail randomly. Perhaps the holes in this card are slightly out of alignment, or the connector that came with it is out of spec with pins that are too small? In any case I had to give up and remove the connector and mount the card separately from the stacked Pi peripherals to get everything to to work.
2) I used the prototyping area but there were no power pins for my op-amp circuit broken out (I needed 5v to ahieve output signal values in the same range as the input.) Taking it from the main connector meant I couldn't plug anything else into the card (kind of a moot point though, see #1.) Adding a mounting hole for 5v power supply next to the prototyping area would be nice.
3) In a fully-utilized configuration, the dac-load GPIO 25 pin is a dear commodity. I'd like a jumper to set it to a fixed value of true as my code does since I'm ok with the load happening through SPI.

Hello

I am sorry you have had problems with our ADC DAC Pi board.

The pins on the GPIO header we use are slightly narrower than those used on some other boards which can occasionally cause connection problems with boards stacked on top of the ADC DAC Pi. One solution we have found to fix this is to bend a slight kink into any problem pins making them press harder against the inside of the other connector.

Thank you for your suggestions on how to improve the design. I will try to add extra power pins and a DAC-load jumper in the next revision of the board.