Welp, that's all I got lol. If you had the race MAF then that would've been your problem but since you have the standard bore then you shouldn't have any issues.
The struggle is real. I'm vacationing in Japan and shot the shit with Ryo over at Seeker for a bit and even he said he's not gonna run his FK8 again until winter 🤣
+1 for Mike Sweeney aka MikeTheTuner. He's local to me and dyno tuned me recently but he also specializes in remote tuning. Very satisfied with the results so far.
If you want a PRL-like downpipe wait for the TSP. I spoke with them the other day and they're about 2-3 weeks out.
https://www.twostepperformance.com/products/high-efficiency-downpipe-upgrade-for-2017-2021-honda-civic-type-r-fk8
Ordered my kit from RHDJapan and got all of it within a week. This was just in the past month or so unless there was a run on Mugen kits recently they should them have them in stock.