I assume you mean LLSP (lightening lane single pass), not single rider. Single rider is a different concept.
Subject to availability, you can have two LLSPs per day. So in one day you could pick 2 of Rise, Tron and 7DMT.
Note: The LLSPs very often sell out in advance so assuming you have hoppers and you are planning to hop to MK that day, I would book the MK LLSP ride(s) you want in advance (as far as possible given your LL booking date) and not wait until the day of to try to book them.
Also Note: If you purchase LLMP for DHS, after you tap in to at least one LL at a DHS attraction you have the option at any time that day to book available same day LLMPs for MK to use after you hop to MK.
One thing that is nice about hopping from HS to MK is that MK frequently has more LL options later in the day, so there should still be some availability.
The downside to starting at HS, is that the morning LLs are tough to get, making rope drop really important.
My recommendation would be to buy ROTR and amd Tron SP so you can take advantage of the first hour at HS to ride stand by instead of RD’ing ROTR. 7DMT often drops to lower waits in the evening as long as it isn’t a crowd level of 8nor higher.