Depends on the watch it's replicating for me.
Don't think I'll bother reluming, say... the Tag Calibre 1 as the gen has weak lume anyway. The PO on the hand, IMO, needs it because the gen is radioactive. All omegas are. I can read books by my 2004 gen moonwatch and its lume areas are minimal.
So, for most of my reps, prolly not, but for some it's a must.
Edit: As mush as i love mechanicals, I also own an atomic^^ digital (gshock) watch. It's awesome. Most accurate watch in the world. I use it to set my mechanicals.