So my understanding of the cap situation (using Spotrac data), and I'm very open to corrections, is that we are currently $2,777,853 over the tax. However, that includes a $1,446,428 in likely-to-be-earned bonus for Jaylen Brown to make the all-star team. Assuming he doesn't, the C's would be $2,777,853 - $1,446,428 = $1,331,425 over the tax.*
So Bol + cash** to OKC would leave the Cs $829,727 under the tax, which would be enough to get a prorated min salary on the buyout market. Of course OKC probably wants to wait to see if they can get a better offer for their space under the threshold. I doubt they will, though I could see Utah sending Ingles, cash and a pick to reduce their tax payment by $26m. Again, the Jazz probably want to wait to see if they can get a useful player for Ingles' expiring deal too.
I see no need to salary dump DS to get under the tax at present. It is useful to have the option in case a) OKC tries to extort a first round pick out of a Bol trade or b) OKC does find a better use for their space.
*Still technically vulnerable to about another million in unlikely bonuses if he makes MVP, DPOY and one of the All-NBA teams.
** The Cs used some cash in the Fernando trade, but I think they have enough left to cover Bol.