Trying to Consolidate Two Water Lines + Tie In a Softener

I’m trying to determine the best way to simplify a mess I’ve inherited. I’ve included an extremely rudimentary (and not to scale) sketch for reference. If you’re wondering how it arrived at this state, I’d be more than happy to explain, but for now I’m trying to keep it simple.

Basically, coming from the well are two main lines – one is 1.5" black poly and the other is 1" PEX. The poly line is the original line that went straight to the utility room, then branches off to all of the various terminations, including the toilets. At some point in the past, the separate PEX line was brought off the main and used to supply only the toilets; the toilets were disconnected from their original supplies, but all of the plumbing was left intact. On this separate toilet line is a filter/softener set up.

What I would like to do is put everything back on one line, have that run through the softener, and reconnect the toilets to their original plumbing. I was hoping I could either cut out the 1" PEX line altogether and add the softener to the poly line in the well house (Option #1 below), or tie the 1" PEX into the poly line in the crawlspace (Option #2 below).

My questions are these:

1. Will either of these work?
2. Which one would be best?
3. If the softener can be added into the poly line, what would be the best way to do this fitting-wise?
4. Is there anything I’m missing or do you have an alternative?

Thank you in advance for any help. I have some basic know-how, but I just wanted some advice on this before I get into trouble.

Regards,
Nate