My own experience (sim exercises only) makes me conclude that there is no right answer here.
I personally view this on a case by case basis.
If you are in congested airspace..ie 30West or US/EU RVSM area's then the 90 degree turn off track is a good option. If you are trans-pacific or somewhere over the middle of Africa etc then in all likelyhood there is no one else within a 100nm anyway...so its less of an issue
This comes down to your overall SA, which on a longer sector, can be reduced due to fatgue, boredom etc...