Played through the update real quick. Not much added by it (the Enna succubus as H-content, a few new equips etc.). And indeed, if you complete the Questline, you lose access to Beverly H-Scenes and Miki as a whole (Combat&Scenes).
Here's the full Save for the game so far, did most content, did not go through much of each Succubi sub path (did a bit of Macky, you'll have to tweak the game Variables&Switches if you want to redo those Scenes; or wait for a Gallery Patch), so it's fresh to start on (also have all skills, good equips, decent Loadout to beat anyone (if you start the combat by using "Energy Stabilization", OP skill) ).
To add Miki back, I made Save 11, still with all the v0.097 Content done too. (if you play from that Save, Miki will remain even if you leave the map, no worries there).
Enna is re-doable quite easily by getting back to her place ("Old Housing Facility", from Witch's House teleport), and either directly choosing Fight, or choosing to Play and wandering around like during the Questline.