The smart mouthguards being used in Super Rugby Pacific have received the backing of one of the coaches but an All Black has questioned the timing of their introduction.
World Rugby has invested several millions of dollars in developing the new technology which can send notifications to pitch-side doctors when a player is impacted.
There was a delay between the data being collected and transferred from the mouthguards during last Friday's season opener between the Chiefs and Crusaders, which resulted in players being sent for head injury assessments at incorrect times.
That has led to criticisms of the technology from some players and coaches, with All Black and Crusaders midfielder David Havili the latest to question whether the introduction of the smart mouthguards to Super Rugby was premature.
"We all agree with Scoot (Scott Barrett) we don't want people getting pulled off for no reason. The fans want to see the likes of Anton (Lienert-Brown) and Quinten Strange on the field as long as you can. If it means not getting them off at the right time, I think that's got to be looked at," Havili said.
"If you look at it under a microscope they are in the players' best interests but in terms of where it's at, at the moment, I would like to have a wee bit more data around it and have the system a wee bit more tight-lockproof."
However, Havili agrees with the reasons behind using the technology.
"It is a gladiator sport, you know, and you are going to have big collisions.
"The mouthguards are a thing where you can track that. In the long scheme of things when they get the data right and the technology is where it needs to be, it will be great for the game."
The New Zealand Rugby Players Association has also expressed concerns, with boss Rob Nichol telling RNZ he feared players might stop wearing the mouthguards if the issues weren't ironed out.
He believes they have been made mandatory too early.
However, the Hurricanes assistant coach Tyler Bleyendaal is backing the use of smart mouthguards in Super Rugby Pacific and he's confident some teething issues will be fixed.
The former Crusaders first-five said they are there to protect the players.
"Trying to get them to fit well has been the main one for the players, but it's all in the name of player welfare and player safety so the players are keen to make it work," Bleyendaal said.
"There's just a few kinks that need to be ironed out as we've seen. We're trying our best to get on board with that (smart mouthguards) and hopefully it becomes a non-issue.
"Like I said it's for a good cause so everyone is trying to make it work."