For the most part... yes, although there's a ton of content missed that way, but it is theoretically possible. You can be "loyal" to any one LI really. All "lewds" are optional that I recall regardless. So, you can have the MC be a solo-LI fella, a various multiple, or a (mostly) all-in. I say "mostly" since you miss some content of some LI's in a few pathing splits (like sis/Ashley Wk9 Date choice), and (to date) you can't be on both Lily and Ivy solos (it's one preferred and then as a threesome or no threesome).
Thanks for replying
I might actually try a Nicole solo path eventually.
She is my second favourite girl after shortcake.
Okay, I've done some analysis on this particular LI playthrough starting from Ch1.
Testing
I've gone back to Ch1 after over a year (and boy, there's some bugs there but that's another subject) and there is some forced content if trying to be solo Nicky (granted it's now an "open" relp so labeling it as cheating is off the table). For example, in Wk3 when you are awarded the task complete of the MC resolving issues with his sister, the dual-masturbation scene is forced if not on Path(Ashley) which of course we aren't since we are playing a pure Nicky run. Otherwise if on Path(Ashley) thinking you'll break it off with her later in testing, you get the fantasy scene for Ashley and no Sis (due to the pathing split where Ashley takes priority in the conditionals).
The most blatant happens again in Wk3 with the SisGrinding scene where it leads to full-blown 69'ing. This happens regardless of trying to temporarily be on Ashley's path (and thinking you'll later dump her ass) to try and keep it pure Nicky.
Keep in mind that by the start of Wk3 Nicky's scenes of her have her imagination now in full cuck queen mode, so take the above with that grain of salt... she's a cuck if you don't kill the relp with her. But killing the relp with her defeats the purpose of a NickySolo run attempt to begin with.
This goes on and on but you get the idea now. Trying to stay on a Nicky only path can only go so far since the relp is "open", she's full cuck, and there's a few forced scenes in the early game with other LI's (either real for the MC or dream/fantasy).
Summary
Now, with that basic branching setup in mind if you make a Ch1 run with no other LI's than Nicky (you'll still get some Sis forced scenes), at the end of Ch1 you can call it quits with Sis (by not claiming to be her boyfriend or retaliating on Brody) and then theoretically have a pure Nicky start going into Ch2 (via export/import). That's about the cleanest way to do it imho.
