Second pitch of dry yeast

I brewed a monster RIS today and pitched with 1968. Gravity at pitching was 1.101, and I still haven't added the 15% sugar I was planning (2.36#).

I'm planning on pitching a pack of S-05 along with the sugar to help with attenuation but I'm not sure if I should just rehydrate and pitch, or actually get it active in a small starter.

I realize that making a starter is usually not recommended with dry yeast but we're usually giving out that advice when it's the first pitch. Will the yeast be ready to ferment if I plunk them in a wort that already has alcohol and no oxygen if they're only rehydrated in water?

I'd make a starter, but that's just me.

dry yeast does not need oxygen to get going. look on danstar's website for info on this.

Well I went with the typical rehydration method and pitched it at the same time as the granulated sugar (which was dissolved and boiled in a bit of wort I saved from the mash leftovers). Things are active again but I guess I don't really know how well the US-05 took to the solution... I guess the proof will be in the FG. If I can get below 1.025-1.030 I'll be pretty happy.