Water to Grain Ratio for Partial Mash

Looking to do a partial mash for my next brew and it seems that as PM is so close to AG, I feel as though I should be following the same basic conventions as if it were an AG recipe. I see the usual suspects citing volumes of around 1.25 to 1.5 quarts of water per pound of grain to ensure good enzymatic conversion for the mash.

Typically I will steep my specialty grains in a 32 L boil pot with 4 gallons of water at 155 F for 30 minutes when I do an extract recipe, lift and let drain completely (no squeezing!), discard the grains and top-up to 6.5 gallons, add my DME and start the boil.

For my next brew (Belgian Blond), following a few leads on this forum, I am doing a PM and using 2.25 Lbs of grain consisting of biscuit, aroma, honey and 2-row pale so the temperature will be held tightly at 158 F for 45 minutes with the grains in one large sock, then placed in a strainer suspended above the pot and sparged with 168 F water.

Questions are;
1) Should I follow the conventional 1.25 to 1.5 qts per pound to steep/mash, or can I stick to my usual 4 gallons, or somewhere in between;
2) How much 168 F water should I sparge with (don’t want to extract tannins…); and
3) Can I just dump the sparge water by the pitcher-load onto the grain sock or do I trickle it slowly and evenly?

You have lots of options, all of which will work.  Honestly, id keep it simple and take a check from the biab folks. Mash your grains in your sock or paint strainer in you full batch of water... 4 gallons of whatever.  Then just pull the sock out and squeeze it dry.  Then proceed as usual for an extract batch.

My response is similar to Tom above.  When I do partial I always keep the grains in a brewer sock.  I never use less than 1.5q per pound of water, but I typically go with the minimum I need to keep the bag fully immersed yet off the bottom of the pot.  I then use however much water I need to get to boil volume as my rinse water.  As long as you have enough water to allow the enzymatic process to work you should be good.