In real life, some old mechanical signal boxes were still kept, with the lever frame being replaced with a panel. Examples include Thorpe-le-Soken, Helpston, and Ryde St John's. It's quite strange how this isn't possible to do in Simutrans. This would be a great feature, as it would save money. Obviously, the max number of signals would be a lower amount than in a proper power signal box. I'd love to see this implemented eventually.
This would involve some significant complexity of work for a relatively minor improvement. For that reason, it is unlikely that this will be a priority for me in the foreseeable future, given the very large amount of higher priority items. However, if this could be done properly without any anomalies or exploits, and with everything being kept entirely consistent both internally and with the reality being simulated, this might be a worthwhile feature.
I am wondering if that's not simply the same as an old signalbox being able to control more modern signals, in which case this would only be a change in the dats?
Or is the issue about simulating the replacement of the lever at some likely rather low cost to allow them controlling more modern signals?