Incase anyone is actually worried it's fake there's also the 27:19 done in chocolate doom, I would imagine it would be more impressive to cheat in two different source ports than to get a good plutonia exit. Also I was thinking about picking up some streaming, but I'm a bit lazy about that.
Anyways, I am indeed new to speedrunning, and I'd say I've done a playthrough of doom 1-2 atleast 15 years ago, and then again around 5 years ago. And the last year a playthrough of plutonia and tnt before the last 2 months of lots of plutonia runs. But I'm not exactly new to playing computer games ^^
I still really want to see plutonia go below 25 minutes, as sub 24 just got to be impossible. I've had other decent runs that would go sub 26, and it feels like most of the RNG is in the early maps. Once you get past the archvile on neurosphere it feels like the run is now all in your hands with cyber demon on map 24 being only exception, even if he hits you the only problem should be low health on map 26.
As for places to improve my run I should just reset if I get 1:10+ on map 4, I could probably save almost 10 seconds on map 5-6. On map 9 it is possible to save another 10 seconds, I lost too much time leading up to the glide. On map 12 I could perhaps try to go for a different strategy which should take 15 seconds, or save 10 seconds compared to if I do my current strat correctly. However it works like 10% of the time, and maybe 20% of the time you'll get 0:25 anyways, so ending 7\10 runs here to try to save 10 seconds would be too much, I don't think I can improve my chances either. Some more plasma ammo on tombstone (missed 40 ammo on map 21) could help bring the time down to 1:45 and I should get a quicker archvile jump on map 24. Then there's the obvious 15 + 10 seconds on the last 2 maps. Of course there are a lot of places were timed can be saved, but the ones I mentioned are to me the most simple ones.
I would expect there to be a good chance to lose time on the first 2 arch vile jumps, they can both cost 10 seconds each or more often end runs. Also I had an amazing map 3, I don't like the idea of doing reset after getting a bad time on this map as well, getting through the first 4 maps is painful enough already. So with some more reset early on and a couple of improvements somewhere it should be enough to get sub 25:00, but I will spend less time on plutonia now that I have a decent time.
Most of my time playing doom from now will probably be spent on other wads, I also want to move on to doom 2 at some point, either 23:25 UV or 29:39 NM would be ridiculously hard to beat, I'd like to give one of them a try, but would require a lot of time and unlikely I'll ever get close. I really enjoy just studying the run itself, figuring out what works best for me for just about each corner of the game, then seeing it all come together for complete run.