Tvheadend

I do it the exact same way (but I use the freesat bouquet feature as a base for dvb-s mapping), it takes me about an hour at most as there is only maybe 30-40 useful channels on DVB-T/T2 I don't bother with the channels that time-share for a few hours a day.

Well, you can try the 'merge same name' feature when you map, but that obviously fails if they're not identical on both carriers.

I used to try to do as above, but in the end I surrendered and have left most of them separate. In some ways, I find it useful to know that BBC ONE HD is on DVB-T and BBC One HD is on DVB-S - I even played with renaming them as such for a while, but then it all got too hard so reverted to leaving them as is. It doesn't harm anything, although does make for a more cluttered EPG.

Kind of lost interest in bouquets...originally I quite liked the simplicity of it, then I found the ordering/channel inclusion was too far removed from what I actually liked, so went the manual route on my new, clean, install.

I'd never noticed the "Merge same name" feature on mapping...

I guess the problem with that might be the picon data that is set (an unmentioned requirement :) )?
Part of the reason I map DVB-S first is that you end up with a channel where the picon info is DVB-S based, and so the one most likely to be found/included in the builders/packs that are available. DVB-T-based picons for Freeview don't seem to be so readily available/comprehensive (unless I've been looking in the wrong places).

You could maybe scan for all services, then select the DVB-S ones and map them - then select the DVB-T ones and map them with the 'merge' option set. I would expect that to merge T into S, so the picons for S would remain. Probably :)

Freeview icons aren't as comprehensive, but they are out there - although I've set some by hand and long since forgotten about them, to be honest, so I don't think I ever had a full set.

Oh, that's an idea. I'll give that a go and see if it works. Ta.