The simple answer is no, you don’t need to fear comeback with voodoo love spells – not if they’re fixed up by a competent spellworker. The bottom line is the spellcaster or conjurer takes all the risk on your behalf.
Plus the idea of comeback or karma is very badly misunderstood in the west. It’s a concept from Indian mysticism that has been picked up by purveyors of new age trends – most of whom aren’t exactly scholars.
Study the annals of Indian mysticism in good scholarly translations (which are hard to find) and you see a wholly different picture to that painted by the new age movement.
One thing that popular ideas of karma miss is that a good number of people generally considered bad live to a ripe old age, often in the lap of luxury. Believers in an afterlife or reincarnation would insist, with somewhat shaky reasoning, that they will get their comeuppance one day.
But when it comes to love spells, the point is there is no cause to worry. Results magick works in conjunction with the ebb and flow of nature and the streams of fate. It adheres to natural law. So if done right, a love spell will not have any comeback for either the client or practitioner.