Stuttering usually means problems/conflicts in the load order, or too many mod stuff loaded all at one. Why you guys just can't read the description, when i precisely stated that your load order must be optimized, if you want no performance issues. Do you think game engine is just magic tinkerer type and will not be loaded by a numerous NPCs who are out where? How do you imagine having much more action on the screen without hammering the game engine performance? Your conflicts in load order what are present initially are just amplified by addition of many new NPCs. Do you expect that to be in another way? 

For example, let's say you have some mod that adds new weapon, any you had non made merged patch for it of don't use proper compatibility mod, because you think you are too good to some load ordering and can get away with the things as they are. Simple conflict with leveled list, of problematic mesh, or texture on weapon gets amplified (multiplied) by WOTC, since number of NPCs in loaded area is increased greatly, so required resources and number of generated errors/trouble from the load order increase in the same pattern. 

And yet, you probably use many weapon/texture/cell edit mods simultaneously, that causes the game engine to be spammed by troubles/errors each of those adds, finally it becomes unmanageable, to the point where game engine struggles immensely just to maintain this mess. If it fails you got CTD, if it manages somehow - you got stutter and performance drop. That is simple snowballing of problems with all mods in load order, when game spawns more content. And if you are a "wise" or ignorant guy and do not pay attention, thinking that you can get away with that, this just cost you a CTDs, stutter, and inability to run some mod combinations normally.

That is why i warned you in description, that you must pay attention to your load order and to resolve conflict mess where. But who reads descriptions anyway? That is for losers, right? I do not say that WOTC is perfect and have no flaws, it probably have, since nothing is perfect. What i say is that you must pay attention to your setup, to make sure that is neat and clean as possible, so CTD and stutter will not prevent you from enjoying the play.

What should you do if you have stuttering?

1. Clean up mess in load order in any way you can, at least use LOOT to take care for some stuff. In some severe cases hand edits with FO4Edit will be required to resolve conflicts by hand. If you need tutorial for hand resolving using FO4Edit, here is link for you: https://www.youtube.com/watch?v=_oG2jlSLptY

2. Optimize your load order and limit number of resource demanding mods you use. You just love those high resolution textures on all the stuff including nuka cola machine or on stupid combat shotgun and crappy outfit, don't you? You love to run in highest graphics everywhere and use some enb's, fog, lightning and weather mods? You love to have settlements build up WAY up more then vanilla limit? You must change your habits, or you will pay with CTD, stutters and FPS. Remove unessential mods, decide ones what are really important for you, make priorities and remove all optional stuff.

3. Re make a clean save and reinstall WOTC after you had made some notable changes in your order, to make sure WOTC is re-initialized with proper internal configuration for your new mod set up. That is done in sequence:

1. Navigate to some interior, for example: basement of one of the houses in sanctuary hills. 
2. Save the game and exit. 
3. Completely uninstall previous version. 
4. Launch the game and load latest save, ignore missing plugin warning. 
5. Make new save (this one would be clean of previous version scripts). 
6. Install new version of the mod. 
7. Load latest save. 
8. Play

4. Make sure WOTC settings set in menu are suit your PC performance. Sure you can max everything on rust bulket, but you can have CTD rain and serious stutters right away. Play with the settings, until you are satisfied with performance, in some cases you may want to try NPC limiter.