You can slice it, clone it and re-use it in different places. Sometimes one short clip with a few tempo changes will be all you'll need.

You can cut, clone and resize the automation clip to suit your needs. Right click the 'Max' knob, and hit paste value. Then find your automation clip in the channel rack, and open up the channel options. If you want the tempo to change instantly, you can right click the node you just added and choose 'Hold'. Or double-up measures before the tempo change Otherwise, the automation changes other people have suggested will work. First, manually set the tempo to 200, then right click it an select 'copy value'. You can grab the tension node between the start and where you added the new node and drag it up or down, to create a mild or steep curve (for a slow, or fast change from one tempo to the next). If you do nothing further, the tempo will change in a linear fashion (gradually getting faster or slower until it reaches the new tempo). You'll see the node move up or down to the new value you just pasted in (the node at the beginning of the clip will be still set at the original tempo) Next, you need to decide how you want the tempo to change from one node to the next. Now, right click the node on your automation clip where you want that tempo > Paste value. Next, right click the tempo display > Copy value. When FL asks if you want to re-stretch all channels now, click 'No'. So change the tempo in the display, to your desired new tempo. The easiest way to set an exact tempo is to copy and paste it from the tempo display. Limit - Corrects any double/half tempo problems (range options appear when the button is selected). Round - Rounds the tempo (removes decimals). If tempo-sync is selected, setting a tempo here will cause FL Studio to stretch/pitch-shift the sample according to this value when loaded. I know you said the event are edited but Idk what it could be. Tempo (BPM) - Sets the tempo in Beats Per Minute. IF there is nothin there check initialized controls. Next, move the node/s to the position in the track where you want the tempo to change. Go to the browser and look under current project and then check the folders for automation on every pattern. It may also be helpful to set the automation nodes to 'hold' mode so the tempo change happens instantly and stays at that value until the next node. Then right-click on the automation node and select paste value. Now it's just a matter of adding nodes, by right clicking anywhere along the length of the clip, on the line that runs from left to right. Right-click on the tempo and select copy value. An automation clip will appear in the playlist, stretching the entire length of the track. Just right click the tempo display > Create automation clip. I couldn't listen to the whole track, because YouTube stopped working.

Fl studio tempo change