Here’s an example streamed asset that causes FPS drops in different environments (see below)
*Note - I have several custom YMAP files to remove certain trash piles, bins and benches around the building, as well as a custom 100-ish object YMAP file to add gates and fencing to the parking area at the side of the building.
1.) Localhost server with me being the only client - when approaching the area, there is an “almost freeze” (drop to ~10 FPS for around 0.5 seconds)
2.) External server (avg. ping is 55-60), same area - a visually longer drop in FPS, no exact times though.
This happens only on first download, later, when the asset is cached, there is no performance impact whatsoever in or around said area.
Here’s some of my rig details which may help:
i7-7700, 1070ti, 16GBs of RAM @ 2133 MHz. GTAV and FiveM installed on a 7.2k RPM HDD. 100 mbps connection (average download speed is 10 MB/s). When running local server + client CPU usage fluctuates near the 70% mark, RAM no more than 10GBs occupied.
LMK if you need more details and I’ll add them as soon as I can 
Edit: I am not the only person with the FPS drop issue with this particular MLO and YMAPs. Two other people (with very different PCs and ping) have tried, so far, on the same server, and they all said they had dips in frame draw times when entering the vicinity of the modified building.