It's never recommended to enter in "custom" scaling percentages - stick with the ones Windows shows in the drop-down.
Does On Center/ConstructConnect support the applications on 4K monitors (and/or, are we planning on PlanSwift plan on making any changes to our software to address any display issues)?
At this time, no. PlanSwift would require significant technology changes to take advantage of 4K resolutions. These changes would provide little or no improvement to the core capabilities of the software nor material benefit for our users. We recommend adjusting your settings to get the best experience you can, however, we feel our resources are best spent providing tangible improvements to the program that will benefit all users.