I am super happy about the Olympian Affair, I want to know more about the characters. I have time to reread the first book, as I remember the overall story and characters but not the details.
I admit I am not super confident on Jim ETA for the next Dresden Book, but perhaps he surprises me 

... yeah... as for the next Dresden, recall at Dragoncon 2021 Jim announced he was at 40% and hoped to finish Olympia in 6 weeks...

yeah, he said editor. Not publisher. not printer. It's progress, but it isn't here. Gonna be months, but that beats years

Harry is Harry, Shadow-Harry is still Harry..

But does Alt-Harry have to be exactly? Same parents, but one Harry takes after mom, one after Dad, sort of like brothers

What about where they first meet and Cowl seems disappointed Harry is not yet heavyweight class? Marcone should have had a much better idea of Harry's power, and a timetravelled older Marcone even moreso. A Justin or Simon who has only seen him from afar (or from a fire?) or not lately would be working on a projection.

... As for lash or Alfred, they are DESIGNED to communicate with humans, it is a key function - in Lash's case, absolutely essential ...

I repeat:  Lash isn't a separate "entity."  She's part of Harry's own mind.

No. She is implanted in his mind. If it was just his mind, how did he learned to speak Etruscan, or Sumerian (is that what the ghouls spoke?), or know how to dislocate his thumb to slip cuffs? Improve his guitar playing? Another entity had to be there whispering in his ear.

The 3rd Law is, "Thou Shalt Not Invade the Mind of Another."  That seems pretty straight, but there's ambiguity on what constitutes an "invasion" (I think, after Peabody, the Council lightened-up a bit in their attitudes toward psychomancy).  "Control" has its own whole Law of Magic!  "Thou Shalt Not Enthrall Another" is the Fourth Law.  Again, it's nice and simple on the face of it, but admits of a large gray zone when you interrogate "enthrallment."

Even a 100% mutual & consensual mindlink spell (such Harry & Elaine used) would previously (pre-Peabody) have been seen as at least highly-dubious (likely contributing to fears & allegations of black magic, tho not seen as proof-positive, telling at trial but only circumstantial evidence).

Now they see the need to work on mental defenses, and so they need to work more robustly with the techniques and methods, and so they need to allow such minor and innocuous magics.

The key issue is willingness.  In particular, reading the mind of someone who hasn't given their active consent is forbidden.

What about talking? Seems the Merlin was giving orders in the mistfiend fight? Did anyone ask for that? That was a conversation, mind reading is snooping. If I invited you in, and go to get refreshments in the kitchen, mind reading is rummaging thru my desk. Not implied by letting you in.

If we look at another UF world, Atticus has a link with Oberon - he "talks" to him, but no more compulsion than any dog owner would have on his pet.  Why can't Harry and Mouse?

I that think Michael is telling Harry he asked in prayer -- and got an answer.  That's not mindlink magic.

Unless a prayer IS a mindlink from a higher being.

But also, recall that most creatures don't get soul-gazed at all.  Outside of humanity itself, I think it's pretty rare.

Maybe you NEED a soul, and non-sentient beings may not usually have that.

That might not be the critical issue.  If forced to guess, I'd guess a "mindlink" spell is possible, but very-much harder than with humans.  Alfred has a link to Harry, but Harry just speaks when he needs to communicate to Alfred.

I suspect a sharp demarcation at "can/cannot soulgaze."  Mindlink spell is (relatively) easy with someone a wizard can soulgaze, relatively-hard with someone who cannot be soulgazed (and Mouse cannot, or it'd have happened -- dog & their owners do look at each other, making eye-contact!).

I don't rule out the possibiliy of a link, just that it is easier with another human. As for lash or Alfred, they are DESIGNED to communicate with humans, it is a key function - in Lash's case, absolutely essential.

Are mental links a violation, or is CONTROL a violation? I don't think Mouse and Harry communicating is a violation, enslaving Mouse would be. (also likely a bad move - I think the beast has mojo). And even Michael has been known to use them - when Kincaid was hurt, Michael said "It's not his time" "how do you know?" "I asked"

I'd also guess that creatures of a certain level don't get auto-soulgazed. I don't think you can stare at Uriel and forge a link unless he permits it.

Elaine is human, Mouse isn't.