I have an Archer C6 (ac1200) as my main dhcp server wifi router, and to improve wifi coverage added an Archer C1200 connected by Ethernet.

Their main specs and features are broadly similar, both dual band, both 4 port gigabit, both 802.11ac, though the C6 offers Mu-Mimo and Beamforming whereas the C1200 has Beamforming Only. 

Also, the C6 can be configured as WDS Bridge, whereas the C1200 cannot. 

As the C1200 was the latter addition, I simply set it up as an access point and created two new wifi networks using different SSIDs. 

For a long time this worked fine with static devices connected to their closest SSID and roaming devices auto changing their wifi automatically as and when needed. 

Then we started to get real problems on the C6 wifi. Either slow or dropping altogether. 

I discovered the addition of the 'smart' switching function which i assume must have been uploaded as a firmware update, and also several forum articles with people saying it had screwed their connections and I think a knowledgebase piece from tp-link saying to disable that feature if drop outs were a problem. I disabled the smart switching but the problem has not gone away. The C1200 access point connection is perfect on 2.4 and 5.0, never any problems, but the main C6 router is a constant pain, always dropping the 2.4. 

If my problem is related in any way to a clash of wifis in the same lan, I could swap the c1200 to be the main router, and add the c6 as the range-extending access point but configured using wds bridge so extending the same single network instead of creating a second separate one within. 

I don't want to do that as it will be a pain in the arse, and as i can't see any way of exporting and importing dhcp permanent ip allocations, the job of recreating 25+ of these will be enough of a bore to put me off doing it if anybody out there can tell me it won't help the situation, or offer an easier/better approach. 

My questions:

Is a bridged, single SSID, wifi network technically advantageous/likely to have less problems than my current two wifi setup?

Can a WDS enabled access point client router be configured for WDS with a host DHCP server host router that does not have the WDS function?

Is there any way of export/import dhcp allocations?

Should I just throw it all in the bin and get a mesh?

Surely there must be something better to do on a Saturday night?