> For the Golden Spike Trail Network, this isn't really a route so I changed the relation to be type=network.

I understand.

> I think it's fine to retain relations for stuff like this as long as they're tagged correctly and don't mess up other tools. 

Unfortunately WMT don't display network relation.

I check Golden Spoke Trail Network. It seem that the following routes are partly or completely part of GSTN : 
- Parley's Trail  — Q39054161 : 9 segments
- Centennial Trail  : 21 segments
- Weber River Parkway : 1 segment
- Ogden River Parkway : 11 segments
- U.S. Bicycle Route 77 — Q108067357: 39 segments
- SR-193 Trail : 1 segment
- Syracuse Trail : 1 segment
- Denver and Rio Grande Western Rail Trail : 9 segments
- Legacy Parkway Trail : 6 segments
- 9 Line Trail : 1 segment
- Jordan River Parkway Trail : 17 segments
- Lehi Rail Trail : 4 segments
- Murdock Canal Trail : 6 segments
- Utah Lake Shoreline Trail : 6 segments

Excluded route : 
- Jordan River Water Trail (canoë)

In Europe we design this type of network as : 
- node network
- super route with routes members