@freeschool the spam issue is more recent. We tend to catch it within 12 hours of spam.. but in the past we used to catch it much quicker because @khird used to run certain scripts that I think we stopped doing (he may just not have the time anywmore).. I have been considering locking registration again to fix that.
As for other instances blocking us, some do, but overall our footprint (how many instances we can talk to) is quite high, and higher than most instances (in fact we used to be int he top 20, though i havent checked recently).
I often notice this because we have had a few people with a few hundred followers after a month leave because they noticed some other servers block us. Then i will follow their new account and notice even after a year their follower count isnt even half of what it was after a month at QOTO. Which happens almost all the time. This is a pretty strong indication that while blocking is legitimate, we have far bigger footprint here still than most servers.