Now that the AutoCAD version is no longer supported, you should optimize commands further. There is no reason something as simple as changing the weld flag type and size should take so much time. It feels unresponsive. This application does not seem to take advantage of any of the modern hardware improvements.

The dialog boxes could also use a rework, with welding flags being the biggest offender. Layout, topside and bottomside parameter should all be on the same page. This layout may have made sense when it was made 25 or more years ago, but we have larger screens today.

Please make it work faster. It will be much more pleasant to work with.