Re: Hand gun can?
Some people like raised sights on their suppressed handguns. I personally do not. It really doesn't take too much practice to shoot a suppressed handgun with occluded sights and score COM hits. You won't typically be getting precise, tiny groups without the clear sights but it depends on what you are trying to achieve.
The raised sights aren't something I feel I need. Also, I do sometimes carry my suppressor-ready hosts and aftermarket raised sights on those hosts might not be "holster friendly".
Regarding the SilencerCo Osprey (which is a fantastic product), on some host weapons the factory sights will clear the suppressor. On other hosts the silencer body might sit just at the top of the front sight post. I've had great success shooting the Osprey even at far distance (up to 100-yards) on a 1911 and P220. With the same hosts I cannot do that with other suppressors the occlude the sights.
Again, it depends on what you are trying to do. I can run a plate rack at 12-yards no problems with a Trident9 or TiRant9 on a G19 and those suppressors completely block the factory sights. The key to shooting any occluded eyesight is to shoot with both eyes open (as you should anyway). Give it a try and you might be surprised how well it can work.
Would I rather see the sights on the host weapon? Of course! But it isn't a requirement for some applications.
Now, on that P22 a Spectre will clear the sights no problem.
Sorry for the pre-coffee ramblings. LOL. Hope this helps in some way.