New Cycle Idea - feedback appreciated

interesting concept you are working with here. Low test with high tren has been discussed in certain circles for years, and the theory behind it is actually solid. Trenbolone is roughly five times more anabolic than testosterone, so running it at higher doses while keeping test as a baseline makes some sense.
A few practical considerations that might help you avoid common pitfalls:
Eight hundred mg of tren is aggressive even for experienced users. The sleep issues you mentioned are just the start. At that level, many people run into appetite suppression, anxiety, and elevated blood pressure that can compound throughout the cycle. You said you tolerate it well, which puts you ahead of most, but pushing 800 mg for four weeks straight is still a heavy load on your cardiovascular system.
Switching from your current cycle to this one at week eight needs careful transition. You are coming off Deca and EQ, which have longer half lives. Even though you are planning to add Primo first and remove EQ, the nandrolone will linger in your system for weeks after your last pin. Running that residual Deca alongside high dose tren is not necessarily dangerous, but it does muddy the waters on how you should manage your sides. Estrogen markers might behave differently than expected.
For the low test piece, 300 mg is enough to keep physiological functions running, but if you push Tren that hard you might see some negative effects on libido regardless of the test baseline. Some users find 400 to 450 mg works better as a support dose when running high tren, even if Tren is doing most of the muscle building work.
Here is what I would suggest if you move forward:
Start the Tren ramp slowly. Week one at 250 mg, week two at 400 mg, then peak at 500 mg if your sleep and blood pressure stay manageable. Jumping straight to 500 or higher can shock your system unnecessarily. Track your resting heart rate daily. If it climbs more than fifteen bpm above baseline, back off.
Add Melatonin or Magnesium Glycinate at night if sleep gets worse. Both are generally safe and can help mitigate some of the CNS stimulation Tren causes. Some people swear by Glytactin for this too.
Keep your Prolactin in mind since high Tren can push that up, especially without any Nandrolone running anymore. Cabergoline on standby, maybe 0.25 mg twice a week if you notice any soft erections or low libido despite adequate test.
And please, get bloodwork done two weeks into the new phase. You need to know what your hematocrit and lipids look like before committing to the full four weeks. That data tells you more than feeling good ever will.
Overall, the concept is viable if you approach it methodically rather than jumping in hot. Respect for doing homework before pulling the trigger. That mindset separates users who have long careers from ones who burn out after two cycles.
Good luck with the plan and feel free to update us on how it plays out.

https://steroidwiki.com/forum/post/11685/
If you know you handle tren pretty well, it's up to you, but I would still be careful about using that much. Even if poor sleep is the only side effect you notice, it can still hurt your recovery, mood, and training in the long run. For me, I prefer to stick with a moderate dose and see how my body reacts instead of following numbers just because someone on a podcast suggested them. Often, the extra side effects just aren't worth the small boost in results.