definitely go to darker beers, but higher gravity isnt always the best if the yeast begins to weaken after a few life cycles. ive neve done it this way, i pour the trub into a sterilized funnel into a beer bottle and save it, then regrow it for the next time. this way you know the yeast is still viable. ive heard many people say that 3 cycles is optimal, but i talked to a commercial brewer in town who says they use their yeast 9-10 times before they throw it out. ive used the same british ale yeast 5 times now and its worked great everytime, except the time i didnt use a starter and my nut brown wouldnt go below 18. i think youre second sequence seems the best, because they are not as highly alcoholic beers, but it probably wouldnt make a difference either way. if you want to reuse yeast though i'd suggest saving it in bottles and making a starter everytime though.