(I'm referring all through here to the Electoral Map and the Regional District Map -- I'll try to make it obvious which I'm referring to, but opening up the maps is likely to make things clearer. Maybe colouring Regional District names differently from Electoral District names will help? Maybe I'll do that in the prose but not the lists of districts.)
So, by starting on the less-populated areas in the north of BC, I dealt with the easy stuff first. This was true in more ways than one actually, because before working on the three most populous areas of BC, the Thompson-North Okanagan, the Lower Mainland and the Capital, I thought I'd deal with the Kootenays. The mapping between regional districts and electoral districts remained pretty strong for the East Kootenay region: the southernmost, most populous area forms Kootenay East, but the remaining portion is grouped with the geographically similar parts of the Columbia-Shuswap regional district to form the Columbia River-Revelstoke electoral one.
No real quibbles there: There's a natural split between the mining corridor along the eastern approach to the Crowsnest Pass and the rest of the Rocky Mountain Trench country up to Golden and over to Revelstoke, so the composition of the Columbia-Shuswap regional district makes a lot of sense in the area of snow removal and other kinds of management -- but this regional district so big that it gets carved up still more. There's a bit of a land-swap between it and Central Kootenay regional district along the Kootenay West electoral district boundary: some of Central Kootenay regional district is included north in Columbia River-Revelstoke electoral district, while some of Columbia-Shuswap regional district is included in the other direction to make Kootenay West electoral district.
Logistics also push Trail into the Kootenay Boundary regional district while it's included (quite sensibly) in the Kootenay West electoral district.
I'm in danger of getting lost in the weeds here, I know, so I'll skip to the thorniest bits of this chunk, which relate to the most populous bits of the Columbia-Shuswap and Okanagan-Similkameen regional districts. The Shuswap lake area of Columbia-Shuswap regional district plus the northwest half of North Okanagan regional district form the Shuswap electoral district. And in the south, while combining all the less urban parts of the Kootenay Boundary and Okanagan-Similkameen regional districts into the Boundary-Similkameen electoral district, urban Penticton, the administrative town for the Okanagan-Similkameen regional district is carved off with additions from elsewhere) into its own Penticton electoral district.
So, one of the mis-givings I had about my scheme -- that it might be messy in parts of the province where there is lots of empty land with a sharp concentration of population in one place -- is borne out. Even in the areas around Metro Vancouver this holds true as electoral districts on the northern edge take in swathes of nearly-unpopulated areas, just so as, you'd think, to put them somewhere.
The statistical over-representation I noticed in the first tranche of Regional and Electoral Districts still holds, mostly, but not in Penticton and Cowichan Valley which are included here. Also, as I was adding these seven regional districts to "what I'd looked at":
North Okanagan, Columbia-Shuswap, Central Kootenay, East Kootenay, Kootenay Boundary, Okanagan-Similkameen, and Cowichan Valley
represented by nine MLAs from the Electoral Districts:
Vernon-Monashee, Shuswap, Columbia River-Revelstoke, Kootenay West, Nelson-Creston, Kootenay East, Boundary-Similkameen, Penticton, and Cowichan Valley
I realized that I had missed a detail around the Mid Island-Pacific Rim electoral district in the first group. The western (most remote) part of Cowichan Valley regional district is included (again, very appropriately) in the much larger Mid Island-Pacific Rim electoral district. So, the over-all average
Regionalized Proportionality wouldn't affect this part yet, but let me untangle the rest of the map.