Could WIS us other means of normalizing, sure, but they do normalize using the log5 method. And deadball pitchers are priced fairly compared to performance of modern pitchers (see the
TWISL thread bumped in main forum). Deadball pitchers value in this league is mostly related to volume of IP and discounts from poor quality seasons having salaries reduced during the dynamic pricing era, which led to them being more prevalent on most rosters. This league looked at balancing roster diversity and banning deadball players was one way to do that.
Even without that large pool of players from 1885-1919, you can see from the blacklistings above there are very few due to players being on 3+ rosters. There is a ton of roster diversity in this league and at this cap in general. I've run a number of fun rosters with $10m hitters and $12m pitchers, had three $5m hitters... etc... you can do a ton of fun things here at this cap.
Generally speaking, I don't draft deadball pitchers period because I find it easier to maximize value from modern pitchers, especially with fatigue, at this cap (literally have a 2022 player in a $30m league right now about to double his RL IP). That said, if I am using my exclusive pick on a pitcher, it's for a deadball pitcher so I can grab a ton of IP in one pitcher and because I can generally draft the modern pitchers I want at any time, so no reason to use an exclusive pick for them. For hitters, same rule mostly applies, I use my exclusive on deadball hitters to grab someone unique or that allows me to build a certain type of team that I can't easily get from modern players, or that I can get from modern players and this allows me one extra player of that type. Only snag a modern hitter as exclusive if it's one of those few low cap studs (Coleman, Thompson, Kingman, etc).