yeah, getting the vehicle shuttle setup could be a problem - maybe have someone drop you off at Nym and park your cehicle at Crane or wherever

an alternative would be to take the Malign to Lac La Croix, down the Namakan to Quetico R and up that to Beaverhouse, then take the northern route back to Nym

2 or 3 days to Poobah (up Poobah Creek is easy enough) depending on what the wind gods do to you on Sturgeon (if windy from the West, you could avoid a lot of Sturgeon by going Lonely-Yeh-Jean-Jean Cr); a day or two on Poobah, a day or 2 down the Malingn/Namakan up Quetico rivers, and 3 days to go from B-house to Nym  would work within your 10 days or so.

south from Poobah ? is probably easier to backtrack to the Malign, down to Tanner L and over to Andrews Creek/Darky R.