I used them to improve the circulation. Be careful about leaving them on too long, do generate heat. Make sure not too tight or magnets can dig in a bit (so be careful about putting a bandage over them). They certainly didn't do any harm, hopefully they helped my girl.
No experience with a suspensory injury, but used magnets and ceremic wraps on my boys check ligament injury earlier this year and I am sure they helped. After first scan was told 9 to 12 months till back in full work, after 2nd scan that changed to 6 months, and indeed he is back in full work after 6 months and all is going very well.
I did check with the vet first who said 'give it a go - won't do any harm'.
All I would say is keep a close eye the leg and if you see any changes you don't like the look of take the wrap off.
its an old injury, hes been off a year now and i had decided to retire him so only looking at them helping with any stiffness etc rather than bring him sound.