Not sure what you mean by "real altitude rise with working static ports" - I'm aware of the effects of blocked pitots and statics on airspeed and/or altitude information - just trying to see your point
Nothing new, just referring back to much discussed effect of locked in pressure (ram and drain hole blocked *) - the 'apparent indicated airspeed' rises with altitude. Obviously most dangerous under take-off climb, which will likely be the design case for pitot tube heating/draining and procedures. Possibilities to climb under 'pitch and power' at cruise height include updrafts and that discussion that the Airbus/AF recommended pitch too high? Higher altitude, lower real air-speeds = lower margins?
* Note linked to your other discussions on sampling/filtering - it is possible to detect this by 'listening to the noise' and there are patented and commercial pressure instruments in the process industries that do "impulse line blockage detection".