I write in English for convenience but I'm Italian.
Since 2007 I have been running a personal forum which has always been based on Olympus, I grew up with phpBB2.
The forum obviously over time was filled with changes and personalized style.
When phpBB.com thought about switching to Ascraeus, effectively breaking the continuity with Olympus, I abandoned everything. I picked it up again a couple of years ago, now deserted, but I made use of it to be able to update it to PHP 8 and later to MySQL(i) 8.0.26. to complete Emoji management, Argon2id Password Hashing, Responsive style etc. etc.
Then I don't remember how, I came across your Fork and only now do I see that by following other similar paths, you have preceded me by many years.
But I kept Olympus without any HTML or database changes, You went further and even updated STK. What can I tell you, really good!
Certainly not all implementations will be to everyone's liking, but the underlying philosophy is certainly appreciable.
I think I will localize your distribution in Italian, and if you think it might be useful, I will send it to you.
A question, however, arises spontaneously: why still use prosilver and not a responsive style?