I haven't paid any attention to these either as it turns out - no-one has as far as I can tell. One thing to look out for, if not mentioned already, is whether or not (most likely not) we see much in the way of "désistements républicains" in the second round. As in, back in 2015, the PS /left stood down in the second round in Hauts-de-France and PACA to block the RN's way. This year, relations between left and righ having soured quite noticeably - it seems rather unlikely that this will happen again.
Or to put it in other words, LR/LREM treading ever more on the RN's turf has served to both normalise the far right - and to very much quash the potential for anti-RN "republican fronts" (quite a few right wing politicos and pundits have already quite explicitely expressed a preference for the far right over the left).
But with the 2022 Prez election in mind would not LREM have an incentive stand down in places where it made it into the second round and RN is strong to back the strongest alternative to RN ?