I have had about 10 or 12 in the last two weeks of which 5 were completed in the last 2 days and 1 is still pending validation.

I only have two machines running HSTB and they seem to come in batches of 2 or 3, sometimes as many as 4 at a time. It really is a game of patience and luck of the draw.

The facts need to be faced. In the last 10 days there have been 4137 units returned. This amounts to an average of 413.7 work units per day. Since this the number returned, I would say it is roghly equivalent to the number issued on any one day. Boincstats currently lists 36687 active users with 268,747 active hosts. Not all of these users and/or hosts are currently seeking TB work units, but if only 10% of the hosts are looking for these work units that would be 26, 874 hosts looking for about 400 units a day. That is why these units are hard to get.
On a slightly different topic, the average time for a work unit is about 12 hours. More recently they have been averaging about 15 hours. This would give about 6210 hours per day of processing(about 259 days of processing per calendar day.)
I have a bit of an outlandish proposal. Perhaps an exclusive subgroup could be formed with a cumulative processing power of about 300 to 350 days per day which would exclusively process TB units. The result of this would be the researchers would still get their research done and those members whose interest is in TB research could have better access to the units in which they are interested. Maybe make it the TB team or some such. People could apply and when there was an opening if some opted out they could then be included. They could also have their queues be at a level where nobody would hoarding work units.
Just a thought.
Cheers

My last WU received in May 2019....

One of my devices has also received seven (7) tasks (on 18 & 19 May):

workunit 677449731
HST1_307241_000065_AC0031_T325_F00068_S00061_1--   Linux Fedora   726   Valid                  5/18/21 16:43:14    5/19/21 17:37:43
HST1_307241_000065_AC0031_T325_F00068_S00061_0--   Linuxmint      726   Valid                  5/18/21 16:43:12    5/19/21 06:16:21

workunit 677449748
HST1_307241_000053_AC0031_T325_F00055_S00061_0--   Linux Fedora   726   Valid                  5/18/21 16:43:14    5/19/21 05:12:15
HST1_307241_000053_AC0031_T325_F00055_S00061_1--   Linuxmint      726   Valid                  5/18/21 16:43:12    5/19/21 09:10:23

workunit 677449740
HST1_307241_000072_AC0031_T325_F00075_S00061_1--   Linux Fedora   -     In Progress            5/18/21 16:43:14    5/28/21 16:43:14
HST1_307241_000072_AC0031_T325_F00075_S00061_0--   Linuxmint      726   Pending Validation     5/18/21 16:43:12    5/19/21 09:16:19

workunit 677449744
HST1_307241_000063_AC0031_T325_F00066_S00061_0--   Linux Fedora   -     In Progress            5/18/21 16:43:14    5/28/21 16:43:14
HST1_307241_000063_AC0031_T325_F00066_S00061_1--   Linuxmint      726   Pending Validation     5/18/21 16:43:12    5/19/21 09:17:18

workunit 677449733
HST1_307241_000066_AC0031_T325_F00069_S00061_1--   Linux Fedora   -     In Progress            5/18/21 16:43:14    5/28/21 16:43:14
HST1_307241_000066_AC0031_T325_F00069_S00061_0--   Linuxmint      726   Pending Validation     5/18/21 16:43:12    5/19/21 06:16:21

workunit 678950344
HST1_307242_000028_AC0007_T325_F00087_S00060_1--   Linux Fedora   -     In Progress            5/19/21 16:54:20    5/29/21 16:54:20
HST1_307242_000028_AC0007_T325_F00087_S00060_0--   Linuxmint      -     In Progress            5/19/21 16:54:12    5/29/21 16:54:12

workunit 678950351
HST1_307242_000036_AC0007_T325_F00095_S00060_1--   Linux Fedora   -     In Progress            5/19/21 16:54:20    5/29/21 16:54:20
HST1_307242_000036_AC0007_T325_F00095_S00060_0--   Linuxmint      -     In Progress            5/19/21 16:54:15    5/29/21 16:54:15

I started WCG 2 months ago and just got my first TB WU.