SwitchResX for Mac

I'm running the latest SwitchResX (4.13.1) on a brand new Mac Air 15", M2. My old computer is a 5K 27" iMac. My goal was to use Mac ScreenShare to continue using my existing iMac as a large screen. Apple will tell you that their list of supported screen resolutions is all that is available. With SwitchResX I was able to create a custom resolution of 2560x1440 HiDPI on my Mac Air, which via ScreenShare appears on my iMac in 5K full screen clarity. There is almost no lag using Adaptive quality settings in ScreenShare because the resolutions match. Please note that in order to create the 2560x1440 HiDPI resolution you will need to create a custom resolution of 5120x2880. This will automatically be detected by SwitchResX as a HiDPI and it will appear in your list of Current Resolutions as 2560x1440 HiDPI. I have also installed EasyRes on my MacAir to be able to switch between resolutions when working directly on the MacAir when not in ScreenShare mode. I highly recommend this app, which is extremely good value at the price. For an instruction video on how to use it go to https://www.youtube.com/watch?v=TtKNqoCbOaI

The main feature I bought this tool for is the creation of a custom resolutions for an ultrawide monitor. This feature however isn't available for M1 based Macs, rendering the tool utterly useless. When asking the company for a refund after purchase, they were confrontational and not accommodating at all. Bad customer service.

My Mac simply refuses to open it. :(

This app itself is OK, but when it comes to updates it's just awful - there is a Check For Updates button, but all it does is tell you an update is available. It doesn't offer any ability to self-update (like just about everything else) nor does it provide you with a link to get the update. I have to go to MacUpdate every time, find the app, go to their website, download it and manually install it again. I have mentioned it to the developer but he has no interest in improving this.

SwitchResX didn't really work for me. The extended resolutions worked perfectly but when I set the resolution higher than 1080 the cursor became VERY jumpy and sluggish, sometimes not responding until I moved it around the screen. At one point I plugged in a plg-n-play wireless mouse to test and see if it was my Magic Trackpad but it was present with the mouse as well. I reset the resolution to factory, restarted, and it seemed ok, at first, but the strange cursor behavior soon returned. I manually tracked down the pref panes and other parts (wasn't an uninstaller with the version I had, or I missed it), restarted my computer and everything was fine again. I really wanted SwitchResX to work but for me it didn't. Hate wasting money but maybe the developer will do more work on it and it may work for me in the future.