Hi,
a small guide how to play the story missions and get the achievements without buying the DLCs

For the basics i'm referencing to this guide from MINIVEE
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3006864543

Now the HowTo:
in the "Store.spell" file you can find near the top e.g.
Story_17_ADHD
This is the name of the Story 17. if you have finished the game and check the list in the .spell file you will see that the DLCs are not listed.

To get their names you need to open
spellogs.log <-- in the same folder where the save folder is located

Here you can find atm with two DLCs released:
[Hero:Story_1_Friend] DAY 130: Checking Progression: special order False
[Hero:Story_1_Friend] DAY 130: Story was played. <---------------------------------- Normal
[Hero:Story_2_Teacher] DAY 130: Checking Progression: special order False
[Hero:Story_13_StickerShop] DAY 130: Checking Progression: special order False
[Hero:Story_17_ADHD] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_01_TravelBlogger] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_01_TravelBlogger] DAY 130: Story not unlocked. <--------------------------------------------- First DLC Story
[Hero:Story_PWM_02_Writer] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_02_Writer] DAY 130: Story not unlocked.
[Hero:Story_PWM_03_Recovery] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_03_Recovery] DAY 130: Story not unlocked.
[Hero:Story_PWM_04_ExamsMom] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_04_ExamsMom] DAY 130: Story not unlocked.
[Hero:Story_PWM_05_ExamsEmily] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_05_ExamsEmily] DAY 130: Story not unlocked.
[Hero:Story_PWM_06_PenpalTim] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_06_PenpalTim] DAY 130: Story not unlocked.
[Hero:Story_PWM_07_PenpalSanjay] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_07_PenpalSanjay] DAY 130: Story not unlocked.
[Hero:Story_PWM_08_Artist] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_08_Artist] DAY 130: Story not unlocked.
[Hero:Story_PWM_09_MemoryTraining] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_09_MemoryTraining] DAY 130: Story not unlocked.
[Hero:Story_PWM_10_Doc] DAY 130: Checking Progression: special order False
[Hero:Story_PWM_10_Doc] DAY 130: Story not unlocked.

Everything with "PWM" is a DLC Story.
Now you take the name, copy one of the old storys in .spell file and change the name. e.g.:

{"Name":"Test Tester1","heroID":"Story_PWM_02_Writer","storyProgress":6,"order":{"Day":162,"Hour":32,"HasMessage":false,"MessageID":"","Orders":[],"Status":"NoOrder","sent":false,"TwitchBudget":0,"moneyInfo":44,"fameBonus":0},"tags":["game","space","pink","red","sweet","worm","pride"],"lovedSticker":15,"newMessage":false,"progressOnDay":167,"LastStickerCheckID":17}

Check the "progressOnDay" near the end and change it to your next day.
You can see the day you are playing either in the sleeping screen or you open yourstore.spellinfo in the save folder.
And change the "storyProgress" to 0, so you can start the story from the beginning

After doing all these changes, starting the game and sleeping one night you should get the new story mission.
Probably you need to change the "progressOnDay" after each mail. Happened for me that the first three messages came on itself, but the rest didn't had to beeing forced to appear.

I hope the guide is at least a bit helpful and we will see how fast the devs will close this gap :-D