This might be stating the obvious here but since you have those linear style roof lifters is there a need at all for latches to hold the roof down or do the lifters hold it tight?
i had been thinking i would not need them, but when i installed my actuators i found they did not move at same rate. pretty close going up but i have 1 slow actuator coming down. i installed a remote control that allows for all actuators to move at once or each one individually, and this has solved the problem. i take the roof down 1/2 way, adjust, then get it to within an inch or two from closing and adjust again. anyway, each actuator does not close at the exact same time, and if i misjudged too much i might get in a situation where it could pull the mount from the roof. also, if a small object was to get lodged between the roof and the wall, it could stop the roof from closing all the way yet the actuator would keep closing, and again, possibly pull the mount out. therefore, a built in about 1/2" of play in the actuator mount, thus, when fully closed, you can, with some effort, lift he roof about 1/2". the long of it is, i will be using tie down near the front. have not yet decided for the rear....i may test it a bit first with just the front.
westsyss had a similar issue in his build
http://www.expeditionportal.com/forum/threads/48351-out-with-the-old-in-with-the-new and thats where i got the idea to build in some play. his solution is a bit more elaborate and well designed than mine, but my roof is much smaller and lighter and i think will work fine.
i have also bought one spare actuator to carry as a safety. i will try this one in place of the "slow" one and maybe it will be closer in rate.