Yes the 1.44M (HD) floppies will work when you format them as 720K (DD) on the MSX.
In theory it’s not ideal because the magnetic layer of HD disks has slightly different characteristics, so real DD disks are better, but I’ve used tons of HD disks in the past without any problems when DD disks became more scarce (nowadays they will be difficult to find I think). If the MSX drive was replaced with a PC drive, you may have to put a piece of opaque tape over the hole on the bottom right side of the disk.
Read again my message, I've edited it. The trick I've mentioned (black tape to hide a hole on disks) is to use MSX disks on PC, but it's not guaranteed to work with recent versions of Windows.
