Yeah, I had a similar experience I'll share FWIW. Being old school I also had analog ignition systems before. I put a used msd7 digital 7530 box in the car from a friends car when he upgraded to the grid system. MSD help is about worthless anymore, I liken it to any other major business. The instructional videos are poorly done and unprofessional. It took me a while to actually figure out how to change things but, to Tony's point we have to advance with the technology/ages. It's been working properly now but, I still bought a used back-up box from another local racer for cheap. I guess that's just prudent anymore? It's a shame that the prices have soared and the quality has plummeted.

Wes, im surprised at you! !

Daytona sensors doesn't seem to be very nitrous friendly. Another option off the table.

ICE has a system for nitrous cars. It will retard the timing up to 20 degrees, but only in 2° intervals.

Well, after trying to make it work...the 6530 (6al-2 programmable), I still have the same issue. After talking w/ MSD tech, they finally agree w/ me that the box itself has a problem. It only does it when it gets hot...not the car itself running hot, but push it outside in the heat of the day for a couple hours and it'll do it. I drove it on a cold day and the car runs perfect. Let the car sit outside on a hot day and then fire it up and it instantly has the 4500 rpm misfire/rev limit. So it's on the way back to MSD for another inspection.
In the mean time I have put all the old analog stuff back in the car (6AL, 8987 start/step retard, 2 step, etc.)

Well, after trying to make it work...the 6530 (6al-2 programmable), I still have the same issue. After talking w/ MSD tech, they finally agree w/ me that the box itself has a problem. It only does it when it gets hot...not the car itself running hot, but push it outside in the heat of the day for a couple hours and it'll do it. I drove it on a cold day and the car runs perfect. Let the car sit outside on a hot day and then fire it up and it instantly has the 4500 rpm misfire/rev limit. So it's on the way back to MSD for another inspection.
In the mean time I have put all the old analog stuff back in the car (6AL, 8987 start/step retard, 2 step, etc.)

The analog stuff either works or is completely dead...at least that's been my experience w/ the 6AL boxes.
I've had high speed misfires w/ the older Digital 6 Plus boxes and the Digital Multi Retard boxes, but otherwise they ran fine.

At this point, I'm all about keeping it simple. If the 6530 comes back, I'll give it another shot. If it still has issues, it's coming out of the car for good and the analog stuff goes back in...for good.
I'm far from a "serious" racer. I mostly test and tune and run the occasional street car/KOS shootout.
I have zero desire to plot a timing curve. All I want to do is pull timing out when the nitrous is activated and have a couple of rev limiters. That's it. I have all the control that I want w/ the nitrous progressive.
I don't want an MSD Grid or anything resembling Holley EFI on this car. I'm not setting the world on fire here w/ my two ton sled.
If this thing would still do a burnout on 20° of timing, I'd just manually pull the timing out, lol.

If this thing would still do a burnout on 20° of timing, I'd just manually pull the timing out, lol.

Ha! That's why I have a dial! Do the burnout and then retard. Old school but it works!

How much do you pull out and what are you using exactly to do it?

As you can read n my "lash" thread, I may be zeroing in on my Digital-6 being bad/erratic. I have been running it since '05, and suspect it has been the source of my 10 years of huge spark scatter. I do know, however, that the brand new MSD retard module I was running with my 6AL digital fried the ignition box. Running great, added the module, and instantly lost the ignition. Wouldn't work even after I took it back out. Cooked the box. I had to cut it out of the system to finish Rocky Mountain Race Week 2020. I had it in there for nitrous, and ended up having to put the spare box in and just manually retard the distributor.

So MSD called me last week to inform me that they cannot duplicate my issue w/ this box. They said they ran it on a "hot box" at 4k rpm for 8 hours and it did fine. I said yep b/c it's fine up until 4500 rpm.
Then he said they put it in the freezer overnight and back on the "hot box" the next day for 8 more hours at 6k rpm w/ no problem.
He said the "hot box" brings the temp up to engine temp. He explained no further.
I said this is interesting b/c I'm confident it's in the box and even one of their tech guys agreed w/ me a few weeks ago when I called to get the RMA number.
He said that's all they can do.