First of all, Good Job on new content that's free from any major bugs

. mobs in there aren't too hard and is soloable on any decently geared class combo. it is also a great gold sink from people looking to lvl up their pets (golden eggs at relatively low prices). and event certs dropping from mobs is even better!
I have 5 suggestions that would make this even better for us:
1) removing runes from the mobs drop tables. if we decide to run all the instances back to back, we would potentially need 42 bag spaces just for all the different mats related to upgrading the cenedrils. so besides the mats; the potential drops are arrows, throwing knives, hp and mp pots, event certs and tier 1-3 runes (and mirror shards but those go directly into the currency page, thanks for that). I believe most people will agree that we do not need tier 1-3 runes any more and would like to get them removed from these mobs at least. I know we can use addons to have these runes deleted as we get them but it would still be nice to have them removed from drop tables all together since arrows and throwing knives can clutter up the bag space really fast and we have to stop to make room so that all things can be looted properly.
2) Currently we do not get any xp/tp from these mobs, I would like xp/tp added to the mobs. This place will be taking most of the limited time we have in the week days and even on the weekends, I think, most people will be farming it. so getting xp/tp on the mobs will help us get much needed tp to max the skills needed.
3) I would like a repeatable quest (perhaps once per day) to get hearts. the only regrettable part of making it a solo instance is that healers are unable to complete it without stating to do dps. so having a quest to get hearts would help them get and rank up cenedrils much more easily. I'm sure others won't mind getting a few more hearts as the hearts required to rank up increases per rank up.
4) Currently bosses drop the same things (and in the same amount) as the mobs. Perhaps having them drop only rare mats and a few extra hearts would be nice.
5) adding an exit portal at the end so that we can exit the instance when we have completed it before time runs out. (hi-jacked from ancientiger's
suggestion to put everything in one place). currently we either have to re-log or run all the way back to the entrance to leave the instance, I have tried the usual being in party and breaking it to leave but since the instances were meant to be solo only that didn't work.
Edit:
a few more suggestions in light of change in availability times and resetting dias cost increase.
6) instead of bounding entries to days, how about allowing a flat entry count for the week. so going of last weekend's allowed entry I can be 9 allowed entries for each group for the whole week. this way people who work on the weekends can still run it during the week as time permits. this leads to point 7 perfectly.
7) having an IS item to add 3 entry counts to each group instead of a reset button that requires you to have dias on your account to reset the entry count for the day. you would definitely see a huge inc in sale by introducing this item in IS.