Probably the biggest problem with this idea is that all of the major geocoding facilities, including Google, say in their terms of service that you're only allowed to use their lat/longs on their own maps. You're not allowed to use Google's API to get the lat/long of an address and show it on a Bing map, but that's exactly what you'd do if Microsoft Edge offered a <map> element.

Furthermore, in addition to violating the geocoders' TOS, the lat/longs won't look right on each others' maps. Lat/longs are hard; maps don't line up perfectly. Lat/longs are relative to your mapping provider.

Just use their SDK, OK?