Those runes are quite nice though. Get enough of them on and I think a single click should (I haven't tested this) fill the altar either completely, or very close to it.
Doing some math based on my tests from my own Altar & runes, each rune is worth +20 LP with each knife click. So a Tier 4 Altar caps out at ~1200LP per knife click, and a Tier 5 Altar a bit over 2000 LP per knife click. So it should be 5 clicks to fill your altar.
No idea how that holds up with the Rituals of Feathered Knife/Well of Suffering. Haven't used them yet.
But I did get up to a Tier 4 Altar & Orb, and I'm using a Bound Sword & Pick! Tier 3/4 is definitely the sweet spot where the mod really starts to be fun. Still working towards Bound Armor.
Edit (for the maths!)
Base Knife - 200 LP - 1 Heart
(All Altars assuming max Runes)
Tier 2 (8 runes) - 360 Lp/heart
Tier 3 (28 runes) - 760 Lp/heart
Tier 4 (56 runes) - 1320 Lp/heart
Tier 5 (92 runes) - 2040 Lp/heart
Now here's the fun bit, That's for Runes of Self-Sacrafice, where the base input (the knife) is the same. So do the runes offer the same flat bonus (20 LP) for the Ritual of Feathered Knife, or the same percentage bonus (200/20 = 10% bonus per rune). This matters especially for Runes of Sacrifice, as the base input can be much higher. You could (theoretically, since I haven't tested) get to the point where you are wasting blood from a Villager in a Tier 5 altar, unless you have capacity upgrades, because it's base input is 2K, and as you can see above, you can get up to a 9.2x multiplier (assuming runes give percent increases, rather then flat ones).