Title-chasers can capture success in Welsh forests; Nicky Grist Stages can see Francis and Edwards close in on honours.
Rhuddlan driver Francis and his co-driver Roberts, from Colwyn Bay, have taken maximum points in their Mitsubishi Evo VIII on all four Championship rounds they have entered so far.
Overhauling them will be no easy task, although it is possible.
Perhaps the biggest threat comes from Dylan Davies. The Subaru Impreza driver from Llanon lies second despite two non-finishes so far this year.
With competitors only counting their six best scores from the eightround series, Davies remains firmly in contention.
Early season leader Andrew Jones has slipped to third place in the overall standings but the Ford Escort driver still heads the Vital Equipment Junior Welsh Championship for drivers under 25, as well as the two-wheel drive category.
There's another tight battle in the Ravenol Welsh Challenge, run in conjunction with the Championship.
With points determined by drivers' performances within their class, it's Francis who leads from Jones, but four drivers are tied in third place with just two points separating the next four drivers.
Also on the Nicky Grist Stages, Colwyn Bay's Matt Edwards looks to complete his MSA British Rally Championship aspirations by taking the BRC2 category with three rounds remaining. A successful weekend will ensure Edwards and navigator Will Rogers are uncatchable with the Ulster Rally and double header on the Isle of Man's Manx Rally remaining.
Swift Group-backed driver Edwards is excited at the challenge, saying: "This event offers a new twist. Events are usually either tarmac or gravel and the format of this event is reminiscent of the 70s and 80s when the Welsh Rally used to take in both surfaces."
Leading the BRC2 category, the Morris Lubricants-supported team have also broken into the top 10 of the overall standings in the series.
Edwards added: "People keep saying we are putting on giant-killing performances - we're just doing what we set out to do.
"The car is well prepared, the driver and navigator are well prepared and everything is looked at in great detail to cover any eventuality."
Dolgellau's Elfyn Evans and co-driver Craig Parry have been seeded at number one for the Nicky Grist Stages.
The DMACK British Rally Team crew lead the MSA British Rally Championship, and they'll be the first away in their Ford Fiesta R5 when the twoday rally festival gets underway on Saturday.
Evans competes on the back of a second-place finish in the WRC class on Rally Poland, a puncture having denied him victory.
He said: "If I had been offered second place earlier in the week, I would have taken it, but I half feel that a win should have been on the cards.
"Second is better than nothing on a weekend like this, and we are still leading the championship, which is really important."
Dolgellau's Sion Ellis continues his ANWCC Rally Championship campaign on the Nicky Grist Stages.
The Landsail Tyres backed driver looks to strengthen his ANWCC championship lead and also build on his third position in class for the Welsh Championship, having missed the previous round last month. Ellis said: "Finances and time constraints forced us to miss the last round of the Welsh, but fortunately we didn't lose too much ground to our championship competitors." Ellis will be joined by Siobhan Pugh, as usual navigator Dan Nieroda has Formula One commitments.