I tested with strong draught of replenishment cause it takes long to craft and is a high level recipe.
As timer I used the ingame last number that is shown on the bar while crafting.
On my alb:
Recipe is grey, no relic bonus, no crafting gear: 23s till completed
Recipe is grey, no relic bonus, with full crafting gear: 14s till completed (50% bonus in total)
On my hib:
Recipe is green, relic bonus of 27%, full crafting gear: 3s till completed (77% bonus in total)
23s - 50% = 11.5s (a good portion faster than reality on a grey recipe)
23s - 77% = 5.29s (a good portion slower than reality on a green recipe [which could slow it down, so it might be even faster as grey recipe])
23s - 50% => 11.5s - 27% = 8.395s (its even slower than reality so that can't be it)
Ok maybe the 23s time without any bonus is wrong. So lets take the 14s from my alb with crafting gear (same as on hib) and lets add only the relic bonus.
14s - 27% = 10.22 (ok, this even more off from the real value..)
TLDR; Math doesn't check out at all.
Is the ingame timer borked that much? Why is the crafting gear bonus seemingly weaker than 50%? Why is the relic bonus seemingly better than 27%?