On the one hand, I think slot neutrality is a little overrated. If you look at the top CFOP solvers, even they solve FR slot last around 50% of the time, and BL slot around 5% of the time. If there's no obvious easy block, there's no harm in leaving FR for last.
On the other hand, sacrificing a ridiculously easy block because you want to solve another block first feels horrible. Even if you're a little less practised and slightly slower at executing your algs in the other slots, you should always take advantage of easy blocks and lucky cases. Anyway TSLE is one of the easiest steps there is to mirror, and there's the ADF trick for TTLL to bring the unsolved corner to the FR slot anyway (although with some algs, I feel a y rotation or d' cancelled into an AUF can sometimes be faster).
PS. I think this goes for all LSLL methods (including ZZ-b and WV), not just ZZ-CT