In the wake of a technical directive from the FIA on the eve of the Montreal weekend to help reduce porpoising, F1 teams were advised they could add a second stay to help stiffen their floor.
Mercedes was the only outfit that elected to go down that route, as it trialled an interim solution on George Russell's car during Friday free practice.
But Mercedes' actions caught the attention of rival teams, who questioned whether or not the FIA had followed the right processes in allowing the extra stay to be fitted.
Although the FIA has the right to change the regulations unilaterally on safety grounds, that process had not been followed through by the rules actually being altered for the Montreal weekend.
That meant in theory the advisory TD allowing a second stay went against the technical regulations, which limits teams to a single stay.
Some of Mercedes' rivals believed that if the team ran the stay in qualifying and the race, then there could be grounds for the team to be protested, as the rules did not match the TD advisory.
Alpine team principal Otmar Szafnauer backed up that view ahead of Saturday's track action in Montreal.
"As far as the process goes, it's a technical directive - and technical directives, as we all know, are not regulations," he said.
"So it could very well be that we shouldn't be running this in qualifying in the race. If teams have brought those stays, I would imagine they could be perhaps looked at after and protested. So it's against the regulation as it stands today.
"We definitely don't have one. And unfortunately, if you do have an extra stay, you can run the car lower and stiffer, and gain some advantage."
While Mercedes committing to running the stays could have prompted action from its rivals, the team has averted any controversy by choosing not the continue with it for the remainder of the Canadian GP weekend on performance grounds.
The team's version that it trialled in practice did not deliver the step forward that it had been hoped, so the squad has gone back to the single stay that is allowed in the rules.
The FIA could elect to push through a formal change to the regulations for the next race at Silverstone to explicitly allow the second stays, with a World Motor Sport Council meeting scheduled prior to the British Grand Prix that could rubber stamp rules tweaks.
