Installing Pool Pilot SWG in pool/spa

I would like to install a Pool Pilot Digital SWG in my 25,000 gal in-ground gunite pool/spa, but the only available space is in between my heater and the three-way valve that controls the flow to the pool or spa. I understand that this placement is not desirable because it can lead to overchlorination when the system is running in spa mode. The pipes after the three-way valve go directly into the ground with less than a foot of vertical distance. Are there any other options for installing the SWG?

A picture would help. If you have a long enough run from the heater to the 3way valve you could move the 3way closer to the heater side. That would give you longer runs from the 3way to the pool and spa.

Thanks. I tried to include a picture, but I don't have permission to post attachements. I'll try to figure out a way to move the three-way valve closer to the heater as you suggested.