Most of it is gonna be fake, you will likely receive a vial of test instead of trest. If you get legitimate trest then I'd swap out your current TRT dose of Test for it mg for mg. You don't need much Trest to see results, and about 200mg/wk is gonna be similar to running a low dose test+tren cycle without the possibility of mental side effects and sleep side effects. Slow gains but it'll do the weird nutrient partitioning thing Tren does that helps turn everything into muscle or however it fuckin works (Someone else might link the science here), so it'll be slow dry gains and the vascularity and strength improvements are about on par with a low tren dose. Nothing insane, but you will be questioning whether you actually took some tren ace by week 2.
Stacking is a tough one because you need to know how YOU respond first. I'd recommend a solo run of this for at least 4 weeks to determine how you respond and then go from there. Most people are not gonna want to run anything wet on this and yes your nipples are gonna leak a little bit but it'll be without a gyno formation- This stuff *shouldn't* develop tissue at the nipple but it still has a lactation effect so be mindful of this. Personal recommendation is stay with Masteron, a dry oral (Var, Tbol, Mtren), maybe EQ but keep an eye on blood pressure if you run high EQ or respond poorly to that, if you're crazy you could pin a low dose of Tren ace too.
For AI, a lot of people overdo it and claim you NEED Letrozole for this to control it- Not true. Arimidex and Asin do work, I don't care if the science says they won't attach to the right receptor or w/e- They do work. Maybe if you run a shit load of it you'll need something more powerful but if you're being conservative it does not require Letrozole or Ralox (seen that one mentioned too) to handle any sides. 0.25mg Arimidex (or 6.25mg asin) every other day is sufficient, or you can wait until things are apparent and use 1mg (or 25mg Asin) Arimidex to knock it out.
The reason you're seeing conflicting reports is because not everyone is getting real Trestolone. The people who get the real stuff can certainly run it without a Test base, all anecdotal and clinical evidence supports that this will do all necessary functions of test in the body by itself. Adding test on top seems like a waste of money, but that's up to you to decide. If you trust your source, drop the test, If not, keep running it. Or if you just think it might stack and give you better gains somehow, keep running it.
Keep in mind though, this drug is about 60 years old and saw no medical usage whatsoever as well as it was not even being used by guys until about a decade ago or so, and while it was available for all Golden Era bodybuilders and the Ronnie Coleman era guys they weren't touching it. We have no long term studies on it, the only prominent name who has talked about it thus far is Tony Huge and he's hit or miss as far as credible info goes, I don't honestly know anyone who claims usage and has some knockout physique or insane lifts, Tony claimed to use it (I believe exclusively) for a contest prep and felt great and looked better than everyone on this board by far I guarantee but he was also selling the shit under his brand name at the time too so it could've just been marketing.
Just be mindful of these things. I don't personally think anyone needs this shit, most people can build a great physique on just Test when we compare them to the 7-something billion people on the planet that look like melted dog shit and can't life 50lbs without needing a 30 minute rest afterward. Test, maybe Anavar is enough for almost anyone outside of competitive strength sports or bodybuilding. Worth trying once just to know, but you probably aren't going to be amazed.