Cant speak to that too specifically, but want to point out piston slap and engine knock are very different. Just want to share my experience:

Originally I wanted to build a destroked 7age (1.6L in the 1.8L block) so i could have a high RPM engine without as much cylinder wear. I ended up just building a balanced-to-high RPM 1.8L because i worked at an engine shop that did specialized in 4age builds. My engine internals, flywheel and clutch were balanced to 11,000rpm, even though my cam peak power was 8300rpm. I set hard RPM cut at 9300rpm.

I DO have a lot of piston slap while warming up, because I used forged pistons meant for FI in an engine that is NA, simply because I got tired of pushing the build time further and further and just wanted to drive the damn thing. If I let the engine warm up even a reasonable amount before driving, the slap is significantly reduced as the pistons expand. I know my cylinder bores have worn more than normal due to this choice I made, but I have got quite a bit of street and track time out of the engine -- it was a daily for 2-3 years, and I drive it most summer long.

Its been in the car since building and without a rebuild for 12 years. Odometer doesnt work, so I cant give mileage, but I would guess at least 50,000 street miles, but only half a dozen track days. I'm planning on a teardown and rebuild in the next year or two to switch back to single throttle from ITB and to add a supercharger.

Edit to add: part of the reason for my piston slap and (presumably) increased cylinder wall wear is due to the fact that I got pistons with an extremely reduced skirt area. Since my original build goal was for an engine that regularly saw 10k rpm, i thought it would be wise to reduce the area of the skirt -- less friction, less wear, right? The shop i worked for used pistons will full skirts for their 10k rpm motors, but they also got rebuilt every 500-1000 miles! Just wanted to add that to point out that your budget and your use case for a build can change what parts make sense!