LoopStabilizer

For long runs that end up as a slideshow once the item count gets silly. It doesn't touch damage, proc chances or proc chains, it only cuts down on the stuff around them. If your run still lags or something breaks, let me know through either discord (360gaggi) or the gitlab page, best with a screenshot of the overlay (F11) :D

what it does

slow motion instead of 1-2 FPS: when the game can't keep up, vanilla tries to catch up with up to 20 ticks in a single frame, which is exactly what makes it a slideshow. With this mod a frame only gets as many ticks as fit into 33 ms (but at least one) and the game slows down instead. Only when the ticks are what is slow though: if it is the drawing, the game keeps its speed
effect limit: once there are more effects in a single frame than anyone could tell apart, the rest (and their sounds) are left out. Below the limit nothing changes
Pocket I.C.B.M.: one missile is fired instead of three and hits three times when it arrives. Same damage numbers and the same rolls for procs, a third of the missiles. Works for everything that fires missiles (ATG, Plasma Shrimp, Disposable Missile Launcher, fireworks, ...)
Sticky Bomb: with enough of them every hit attaches a bomb. Here a bomb takes the ones along that get attached to the same enemy within the next quarter of a second and goes off once for each of them. Same damage numbers, far fewer bombs
Ceremonial Dagger: the three daggers of a kill go out as one that hits three times, each time with the roll for a crit that dagger would have had
XP orbs: they are only there to look at, the XP comes from the server either way. Once more than 60 of them showed up within a second, the orbs of further kills are left out
Electric Boomerang: all the ones thrown in the same instant fly the very same path, hundreds of them inside each other. Here only one of them flies and hits once for each of them. Same damage numbers and the same rolls for procs
boomerangs (Electric Boomerang, Sawmerang): in vanilla they fly after you until they reach you, with no time limit. Once you are faster than them they never do, so thousands of them end up following you around. Here they give up after 2 seconds on their way back
kill chains: what a kill sets off (Gasoline for one) is worked off inside of the hit that killed. In a crowd where everyone dies to the explosion of the one before them, vanilla nests that as deep as there are enemies and crashes at around a hundred. Here a kill that is nested too deep waits for the ones before it, still in the same instant
Warbanner: every level up puts one down and vanilla keeps all of them until the stage is over, which ends in hundreds of them on top of each other. Here a new banner takes the place of the older ones standing close to it. Their buff doesn't stack, so there is nothing to lose but clutter
Plasma Shrimp: fixes vanilla looking the missile effect up in the asset system again for every single missile
overlay (F11): FPS, ticks per frame, hits per second, which projectiles there are the most of and so on, to see what is actually going on

settings

In the config file or ingame if you have Risk of Options. All of them apply right away, also in the middle of a run.

Limit ticks per frame / Tick time budget: how many milliseconds the ticks of a single frame may take together. Lower is smoother, higher keeps the game at full speed for longer
Limit effects / Max effects per frame / Max of the same effect per frame / Max XP orbs per second
Merge ICBM missiles
Merged missiles hit three times: turn it off and a merged missile hits once with three times the damage instead. Less work for the game, but it only rolls for procs once
Merge sticky bombs / Sticky bomb merge time: for how long a bomb takes others along. They go off together with it, so up to this much earlier than on their own. Higher means fewer bombs, but more explosions at the same moment
Merge boomerangs
Limit boomerangs / Max boomerang return time (vanilla: no limit): boomerangs keep hitting what they fly through on their way back, with a 0 they are gone the moment they turn around and those hits are lost
Boomerang limit in real time: counts that time in real seconds instead of game seconds. In slow motion the boomerangs are then gone as quickly as at full speed, but they do not get as far and hit less for it
Merge daggers
Limit kill chains
Limit banners / Min distance between banners: how close an older banner has to stand to a new one to be replaced by it, in percent of its range
Show overlay / Toggle overlay

There are also debug keys for trying things out without playing for hours first, off by default (section "Debug"). Once turned on:

F6 makes the run count as 60 stages later
F7 moves the timer 300 minutes forward
F8 gives every player a pile of every common, uncommon and legendary item
F9 does all three of them at once
F10 spawns 20 enemies of the current stage around you

Host only, the keys and all the numbers can be changed.

multiplayer

nobody else needs the mod
the tick limit, the effect limit (XP orbs included) and the overlay only count for you
missiles, sticky bombs, boomerangs, daggers, kill chains and banners are handled by the host, so those only do something if the host has the mod

optional mods

Risk of Options: settings menu
Uncap player level and Uncap monster level: for the kind of run this mod is made for

good to know

if the target dies before a merged missile has used all three hits, the hits that are left fly on to the next enemy as a new missile, the way the other two missiles would have in vanilla. The only difference: when two hits are left they go for the same enemy instead of maybe two different ones
fireworks explode instead of hitting a single target, with an ICBM they always go out as one with three times the damage
slow motion means the run timer slows down with it