I am still on both sides of this and rather than upping contact I’d lessen it slightly.
For me, yes lovely to be thought of, but then also, as you intuit chippy, it places an extra burden because I know a reply is expected, even if I am feeling unable to reply at all
Once every 6months actually worked for me with maybe an ad hoc extra thrown in - enough to know I wasn’t forgotten but not placing any extra strain re replying that more regular messages would have.
There is a friend of my DC who has different issues but similar outcome, and DC was annoyed at first but is more understanding now, two or three messages a year doesn’t create the same frustration for DC and it puts minimal pressure/guilt on the friend whilst leaving the door open.
If you haven’t had reply just dial it back slightly - preface it with a text if you prefer saying you don’t want to add any pressure so will text a bit less often but door (or rather phone!) always open
If you prefer to stop the contact that’s ok too, you may need a more regular friend, that’s not an awful thing to feel either
If you can reframe this friendship, even for now, as contact quarterly or 2-3 times a year though it might lessen your worry/annoyance (& friend’s as that might also be the feelings - worry at losing you/annoyance at having regular texts they feel guilt at not replying to)
Each relationship we have is unique & may change over time so all of the above might help or not, just wanted to give a perspective of less contact being an option
I’d’ve ended up blocking any friend or even family that messaged every day because for me that would have felt incredibly intrusive
Try and find a compromise of contact that keeps the door open but not occupying you or your friend’s headspace in a negative way