Smoke from front of engine (m57) 2010.

[Diesel Spectre]

Hey all,
So I’ve started to smell exhaust (?) inside the cabin while driving this last week. Leading up to this, I’ve been chasing a “belt squeal” like noise for months. Under the hood I see smoke coming from between the heat shield and small turbo. I work a lot so I brought it to the shop Thursday. Friday they called me and said both turbos failed due to the dpf being clogged. They can replace the turbos for $11k but I’d have to get the dpf cleaned elsewhere. They didn’t remove anything (that I know of) to come to this conclusion, just heard the noise and saw the area the smoke came from and called it. I’m not getting any codes related to boost (although a few months ago, I dig get one). After they did me that huge favor (which I declined), I pulled the rad fan and filtered air pipe off and had someone try to start it. Now I can see smoke coming from what looks like under the vacuum pump and the edge of the valve cover behind the small turbo in the front corner of the engine. I just can’t tell exactly where. I doesn’t look like the egr cooler connection. It’s got 200k plus miles so I’m going to just do the vcg and vacuum pump.
I believe the noise I was chasing was due to an exhaust manifold leak from either a cracked manifold or a broken stud. I plan to pull the small turbo and the exhaust manifold to inspect and re seal. As such I’m spending a small fortune on gaskets anyway so I’m thinking I should just pull the large turbo as well. That will give me a chance to replace the oil feed lines to both turbos since they all have over 200k miles.
Q1) am I wasting my time trying to limp along with 2 tired old turbos? Would you just rebuild or replace? Go hybrid or factory? New CHRA or send it out?
Q2) the dpf is original and although not clogged, will come out for the large turbo replacement. Would you replace w/ new, clean the existing one, or “upgrade” the downpipe & tune?
Q3) the only thing maintenance wise that hasn’t been done are the timing chains, guides & tensioners. Am I wasting my time/ money by not doing them (like on the N57) or should I leave them alone?
Q4) am I throwing good money after bad here and should cut my losses? The current car market is not conducive to “upgrading” and I have quite a bit into this thing to keep it in good reliable condition. I absolutely love driving it still and new diesels (for commuting , not hauling) are getting scarce.
This is my daily driver (in NJ) so all of this will cause me to find alternate transportation for work (140 miles/day) so the faster I can get back together and on the road, the better.
Comments, concerns, gripes & complaints all welcome. It will help me refine the workflow/ timeline and help me identify all the various gaskets, seals, stretch bolts, etc. I’ll need to do the job. I’ve never had the turbos out or the valve cover off so some of this will be new to me on the diesel.
Thanks in advance,