How much increase? Theory says it should.
Thanks for mentioning that Milon. It cannot be stressed enough.
Rather than "100 hours or annually", I'd suggest developing a cleaning schedule based on early observation of
the particular installation. Technically, it is not the valve which needs cleaned, but rather, the tubular tap into the exhaust system. There have been reports of total blockage at less than 50 hours for Anti-Splat RV-10 exhaust taps mounted on the tailpipe. Even after establishing a rate of accumulation, I'd keep an eye on it, as it may accumulate coke more rapidly as the engine ages and puts more oil out the breather. A change in the usual operating RPM can also make a difference.
Exhaust tap on my 390. It's welded, not clamped. Note bracing; I'm not a big fan of just welding a tube into a hot, vibrating header pipe and allowing it to cantilever without support. The disk is a heat sink; the reed valve stays cool (yes, I measured).
This is the coking problem. The little bit of aerosol oil which reaches the hot exhaust tap can accumulate and eventually block the tap. It seems to build up as a ring of material, but individual applications may vary.
The tap as shown would go more than 140 hours without blockage. One experiment was to see if the rate of accumulation could be slowed even more by installing an insulated liner tube:
It's been in there a few hundred hours now. I clean with an appropriately sized drill bit at each 50 hour oil change, so I've had plenty of opportunity for observation. In my opinion, it didn't result in any significant improvement. Although it may accumulate coke at a slower rate, the smaller ID is faster to block. I'll probably remove the liner tube the next time the pipes are off the engine.
In any case, all installations should have a relief valve tee'd into the line between the separator and the exhaust tap. It's the same NAPA #2-29000 reed valve, installed so vacuum keeps it shut and positive pressure cause it to open. It just sits there doing nothing most of the time, but if the exhaust tap should coke shut, engine case pressure will vent via the relief valve and the engine won't blow seals. I'm aware of at least one instance where it happened and the relief worked, so just do it.
This particular relief valve has had the integral mounting nut machined off to save a few ounces.