glad that helped. I can't explain why, but I have noticed that if you want an expon env with tied notes, as opposed to say linseg, then transeg will work accurately where the others (expon/expeg) don't seem to.

So for example: 

kfrq transeg p6, idur, 2, p7

will create an expon freq env which drops from 14000 to 500 on the first note & remain at 500 Hz for the duration of the tied notes.

I was recently working on this for my own monosynth instr, referencing the Csound Journal article: 

https://csoundjournal.com/2005fall/tiedNotes.html#:~:text=To%20use%20the%20tied%20notes,the%20the%20same%20instrument%20number.r.

I found the process a little (very...) convoluted; I also wanted a more gated sequencer type instr that could also create legato lines & a smoothly modulating filter freq so I opted for a trigger instr passing some local and global variables finding it a far simpler approach (notes in table or array vs score) although there are pros & cons to it. Here's an example: 

 https://www.dropbox.com/s/pq1yp6ymzjmkixi/gated_arp_sequencer.mp3?dl=0

But if you're using Blue then it's probably a moot point.