Yes, a winning lottery ticket and a US style garage wouldn't be turned down! The N + 1 is a powerful draw.
More broadly, it's a fascinating subject: how many bikes a person needs, or wants? That's another thread discussion.... like this:
https://www.cyclechat.net/threads/one-bike-only.230682/
I'm a signed up member of the horizontal top tube club too, though I acknowledge Mike Burrows was radical & highly influential with his TCR design at Giant.
Michele Bartoli was considered to be of the first pros to champion the idea of riding a tiny frame, showing metres of seat post, with a handlebar stem position as low as possible. That's ok if you're a professional road racing cyclist with decent flexibility...
Back in the real world, it was very popular & quickly taken on by shops & gullible* amateurs like me. Who, after a decent 90-95 miles out every Sunday with a club, would end up hardly able to walk, like Champion in the brilliant Belleville Rendezvous (from 0.43 in the clip):
View: https://www.youtube.com/watch?v=be_eolFDZTo
Ironically, it was the exact opposite fashion in the early eighties when we got the biggest frame available and had the saddle set at the seat cluster.
I like the adjustability of the quill stem - the bars can be set above, level or below the saddle. Diacompe's XL or Nitto's Technomic offer extended range.
Either I can start a lot of yoga/ pilates and try to continue to enjoy a wonderful racing bike, or transfer the wheels & gears to the 531 (to be cold set to 130mm) which will realistically fit well into older age, and take 32mm tyres with mudguards...
*Kudos to the writer at Wikipedia for a fantastic definition: 'Gullibility is a failure of social intelligence in which a person is easily tricked or manipulated into an ill-advised course of action'